Global climate change is not a future problem. Changes to Earth’s climate driven by increased human
emissions of heat-trapping greenhouse gases are already having widespread effects on the environment:
glaciers and ice sheets are shrinking, river and lake ice is breaking up earlier, plant and animal geographic
ranges are shifting, and plants and trees are blooming sooner.

Effects that scientists had long predicted would result from global climate change are now occurring,
such as sea ice loss, accelerated sea level rise, and longer, more intense heat waves.

Some changes (such as droughts, wildfires, and extreme rainfall)
are happening faster than scientists previously assessed. In fact,
according to the Intergovernmental Panel on Climate Change (IPCC) — the United Nations
body established to assess the science related to climate change — modern humans have
never before seen the observed changes in our global climate, and some of these changes
are irreversible over the next hundreds to thousands of years.

Scientists have high confidence that global temperatures will continue to rise
for many decades, mainly due to greenhouse gases produced by human activities

The IPCC’s Sixth Assessment report, published in 2021, found that human
emissions of heat-trapping gases have already warmed the climate by nearly 2 degrees Fahrenheit
(1.1 degrees Celsius) since 1850-1900.1 The global average temperature is expected to reach or
exceed 1.5 degrees C (about 3 degrees F) within the next few decades. These changes will affect all regions of Earth.

The severity of effects caused by climate change will depend on the path of future human activities.
More greenhouse gas emissions will lead to more climate extremes and widespread damaging effects
across our planet. However, those future effects depend on the total amount of carbon dioxide we emit.
So, if we can reduce emissions, we may avoid some of the worst effects.

What’s the difference between climate change and global warming?

The terms “global warming” and “climate change” are sometimes used interchangeably, but "global warming" is only one aspect of climate change.

“Global warming” refers to the long-term warming of the planet. Global temperature shows a
well-documented rise since the early 20th century and most notably since the late 1970s.
Worldwide since 1880, the average surface temperature has risen about 1°C (about 2°F), relative to
the mid-20th century baseline (of 1951-1980). This is on top of about an additional 0.15°C of
warming from between 1750 and 1880.

“Climate change” encompasses global warming, but refers to the broader range of changes that are
happening to our planet. These include rising sea levels; shrinking mountain glaciers; accelerating
ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times.
These are all consequences of warming, which is caused mainly by people burning fossil fuels
and putting out heat-trapping gases into the air.

Global temperature rise from 1880 to 2022. Higher-than-normal
temperatures are shown in red and lower-than-normal temperatures are shown in blue.
Each frame represents global temperature anomalies (changes) averaged over the five years
previous to that particular year. Credit: NASA Goddard Space Flight Center/NASA Scientific
Visualization Studio/NASA Goddard Institute for Space Studies.

What Is Climate Change?

Climate change is a long-term change in the average weather patterns that have come to define Earth’s local,
regional and global climates. These changes have a broad range of observed effects that are synonymous with the term.

Changes observed in Earth’s climate since the mid-20th century are driven by human activities, particularly
fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere, raising Earth’s
average surface temperature. Natural processes, which have been overwhelmed by human activities, can also contribute
to climate change, including internal variability (e.g., cyclical ocean patterns like El Niño, La Niña and the Pacific
Decadal Oscillation) and external forcings (e.g., volcanic activity, changes in the Sun’s energy output, variations in Earth’s orbit).

Scientists use observations from the ground, air, and space, along with computer models, to monitor and study
past, present, and future climate change. Climate data records provide evidence of climate change key indicators,
such as global land and ocean temperature increases; rising sea levels; ice loss at Earth’s poles and in mountain
glaciers; frequency and severity changes in extreme weather such as hurricanes, heatwaves, wildfires, droughts,
floods, and precipitation; and cloud and vegetation cover changes.

“Climate change” and “global warming” are often used interchangeably but have distinct meanings. Similarly, the
terms "weather" and "climate" are sometimes confused, though they refer to events with broadly different
spatial- and timescales.

What Is Global Warming?

Global warming is the long-term heating of Earth’s surface observed since the pre-industrial period
(between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases
heat-trapping greenhouse gas levels in Earth’s atmosphere. This term is not interchangeable with the term "climate change."

Since the pre-industrial period, human activities are estimated to have increased Earth’s global
average temperature by about 1 degree Celsius (1.8 degrees Fahrenheit), a number that is currently
increasing by more than 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade. The current warming
trend is unequivocally the result of human activity since the 1950s and is proceeding at
an unprecedented rate over millennia.

Weather refers to atmospheric conditions that occur locally over short periods of time—from
minutes to hours or days. Familiar examples include rain, snow, clouds, winds, floods, or thunderstorms.

Climate, on the other hand, refers to the long-term (usually at least 30 years) regional or
even global average of temperature, humidity, and rainfall patterns over seasons, years, or
decades.

The Causes of Climate Change

Four Major Gases That Contribute to the Greenhouse Effect:

FORCING: Something acting upon Earth's climate that causes a change in how energy flows
through it (such as long-lasting, heat-trapping gases - also known as greenhouse gases).
These gases slow outgoing heat in the atmosphere and cause the planet to warm.

Carbon Dioxide
A very important component of the atmosphere, carbon dioxide (CO2)
is released through natural processes (like volcanic eruptions) and through
human activities, like burning fossil fuels and deforestation.
Human activities have increased the amount of CO2 in the atmosphere by 50% since the
Industrial Revolution began (1750). This sharp rise in CO2 is the most important
climate change driver over the last century.

Methane
Like many atmospheric gases, methane comes from both natural and human-caused sources.
Methane comes from plant-matter breakdown in wetlands and is also released from landfills
and rice farming. Livestock animals emit methane from their digestion and manure.
Leaks from fossil fuel production and transportation are another major source of methane,
and natural gas is 70% to 90% methane. As a single molecule, methane is a far more effective
greenhouse gas than carbon dioxide but is much less common in the atmosphere. The amount of
methane in our atmosphere has more than doubled since pre-industrial times.

Nitrous Oxide
A potent greenhouse gas produced by farming practices, nitrous oxide is released during
commercial and organic fertilizer production and use. Nitrous oxide also
comes from burning fossil fuels and burning vegetation and has increased
by 18% in the last 100 years.

Chlorofluorocarbons (CFCs)
These chemical compounds do not exist in nature – they are entirely of industrial origin. They were used as refrigerants,
solvents (a substance that dissolves others), and spray-can propellants. An international agreement,
known as the Montreal Protocol, now regulates CFCs because they damage the ozone layer. Despite this,
emissions of some types of CFCs spiked for about five years due to violations of the international agreement.
Once members of the agreement called for immediate action and better enforcement, emissions dropped sharply starting in 2018.

Another Gas That Contributes to the Greenhouse Effect:

Water Vapor
Water vapor is the most abundant greenhouse gas,
but because the warming ocean increases the amount of it in our atmosphere,
it is not a direct cause of climate change. Rather, as other forcings (like carbon dioxide)
change global temperatures, water vapor in the atmosphere responds, amplifying climate change
already in motion. Water vapor increases as Earth's climate warms. Clouds and precipitation
(rain or snow) also respond to temperature changes and can be important feedback mechanisms as well.

Human Activity Is the Cause of Increased Greenhouse Gas Concentrations
Over the last century, burning of fossil fuels like coal and oil has increased the concentration of
atmospheric carbon dioxide (CO2). This increase happens because the coal or oil burning process
combines carbon with oxygen in the air to make CO2. To a lesser extent, clearing of land for agriculture,
industry, and other human activities has increased concentrations of greenhouse gases.

How do we know what greenhouse gas and temperature levels were in the distant past?
The industrial activities that our modern civilization depends upon have raised atmospheric
carbon dioxide levels by nearly 50% since 17502. This increase is due to human activities, because
scientists can see a distinctive isotopic fingerprint in the atmosphere.

In its Sixth Assessment Report, the Intergovernmental Panel on Climate Change, composed of
scientific experts from countries all over the world, concluded that it is unequivocal that
the increase of CO2, methane, and nitrous oxide in the atmosphere over the industrial era is
the result of human activities and that human influence is the principal driver of many changes
observed across the atmosphere, ocean, cryosphere and biosphere.

How do we know what greenhouse gas and temperature levels were in the distant past?

Ice cores are scientists’ best source for historical climate data. Every winter, some snow coating Arctic
and Antarctic ice sheets is left behind and compressed into a layer of ice. By extracting cylinders of ice
from sheets thousands of meters thick, scientists can analyze dust, ash, pollen and bubbles of atmospheric
gas trapped inside. The deepest discovered ice cores are an estimated 800,000 years old. The particles trapped
inside give scientists clues about volcanic eruptions, desert extent and forest fires. The presence of certain
ions indicates past ocean activity, levels of sea ice and even the intensity of the Sun. The bubbles can be
released to reveal the make-up of the ancient atmosphere, including greenhouse gas levels.

Other tools for learning about Earth’s ancient atmosphere include growth rings in trees,
which keep a rough record of each growing season’s temperature, moisture and cloudiness
going back about 2,000 years. Corals also form growth rings that provide information about
temperature and nutrients in the tropical ocean. Other proxies, such as benthic cores,
extend our knowledge of past climate back about a billion years.

Evidence Shows That Current Global Warming Cannot Be Explained by Solar Irradiance
Scientists use a metric called Total Solar Irradiance (TSI) to measure the changes in
energy the Earth receives from the Sun. TSI incorporates the 11-year solar cycle and solar flares/storms from the Sun's surface.

Studies show that solar variability has played a role in past climate changes.
For example, a decrease in solar activity coupled with increased volcanic activity
helped trigger the Little Ice Age.

But several lines of evidence show that current global warming cannot be explained by changes in energy from the Sun:

Since 1750, the average amount of energy from the Sun either remained constant or decreased slightly3.
If a more active Sun caused the warming, scientists would expect warmer temperatures
in all layers of the atmosphere. Instead, they have observed a cooling in the upper
tmosphere and a warming at the surface and lower parts of the atmosphere.
That's because greenhouse gases are slowing heat loss from the lower atmosphere.
Climate models that include solar irradiance changes can’t reproduce the observed
temperature trend over the past century or more without including a rise in greenhouse gases.

What Is Climate Change?
Climate change describes a change in the average conditions — such as temperature and rainfall —
in a region over a long period of time. NASA scientists have observed Earth’s surface is warming,
and many of the warmest years on record have happened in the past 20 years.

Weather describes the conditions outside right now in a specific place. For example,
if you see that it’s raining outside right now, that’s a way to describe today’s weather.
Rain, snow, wind, hurricanes, tornadoes — these are all weather events.

Climate, on the other hand, is more than just one or two rainy days. Climate describes the
weather conditions that are expected in a region at a particular time of year.

Is it usually rainy or usually dry? Is it typically hot or typically cold? A region’s climate is
determined by observing its weather over a period of many years—generally 30 years or more.

So, for example, one or two weeks of rainy weather wouldn’t change the fact that Phoenix typically
has a dry, desert climate. Even though it’s rainy right now, we still expect Phoenix to be dry
because that's what is usually the case.

Climate change describes a change in the average conditions — such as temperature and rainfall — in a
region over a long period of time. For example, 20,000 years ago, much of the United States was covered in
glaciers. In the United States today, we have a warmer climate and fewer glaciers.

Global climate change refers to the average long-term changes over the entire Earth. These include warming
temperatures and changes in precipitation, as well as the effects of Earth’s warming, such as:

Rising sea levels
Shrinking mountain glaciers
Ice melting at a faster rate than usual in Greenland, Antarctica and the Arctic
Changes in flower and plant blooming times.

Earth’s climate has constantly been changing — even long before humans came into the picture. However, scientists
have observed unusual changes recently. For example, Earth’s average temperature has been increasing much more
quickly than they would expect over the past 150 years.

How Much Is Earth’s Climate Changing Right Now?

Some parts of Earth are warming faster than others. But on average, global air temperatures near
Earth's surface have gone up about 2 degrees Fahrenheit in the past 100 years. In fact, the past five
years have been the warmest five years in centuries.

Many people, including scientists, are concerned about this warming. As Earth’s climate continues to warm,
the intensity and amount of rainfall during storms such as hurricanes is expected to increase.
Droughts and heat waves are also expected to become more intense as the climate warms.

When the whole Earth’s temperature changes by one or two degrees, that change can have big
impacts on the health of Earth's plants and animals, too.

There are lots of factors that contribute to Earth’s climate. However, scientists agree that Earth has been
getting warmer in the past 50 to 100 years due to human activities.

Certain gases in Earth’s atmosphere block heat from escaping. This is called the greenhouse effect. These gases
keep Earth warm like the glass in a greenhouse keeps plants warm.

Human activities — such as burning fuel to power factories, cars and buses — are changing the natural greenhouse.
These changes cause the atmosphere to trap more heat than it used to, leading to a warmer Earth.

What are greenhouse gases?
Greenhouse gases are gases in Earth’s atmosphere that trap heat.
They let sunlight pass through the atmosphere, but they prevent the heat that the sunlight brings from leaving
the atmosphere. The main greenhouse gases are:

Water vapor
Carbon dioxide
Methane
Ozone
Nitrous oxide
Chlorofluorocarbons

Greenhouse gases are gases that can trap heat. They get their name from greenhouses.
A greenhouse is full of windows that let in sunlight. That sunlight creates warmth.
The big trick of a greenhouse is that it doesn’t let that warmth escape.

That’s exactly how greenhouse gases act. They let sunlight pass through the atmosphere,
but they prevent the heat that the sunlight brings from leaving the atmosphere. Overall,
greenhouse gases are a good thing. Without them, our planet would be too cold, and life as
we know it would not exist. But there can be too much of a good thing. Scientists are worried
that human activities are adding too much of these gases to the atmosphere.

How Do We Know Climate Change Is Real?
While Earth’s climate has changed throughout its history, the
current warming is happening at a rate not seen in the past 10,000 years.

According to the Intergovernmental Panel on Climate Change (IPCC),
"Since systematic scientific assessments began in the 1970s, the influence
of human activity on the warming of the climate system has evolved from theory to established fact."1

Scientific information taken from natural sources (such as ice cores, rocks, and tree rings)
and from modern equipment (like satellites and instruments) all show the signs of a changing climate.

From global temperature rise to melting ice sheets, the evidence of a warming planet abounds.

The rate of change since the mid-20th century is unprecedented over millennia.
Earth's climate has changed throughout history. Just in the last 800,000 years, there have been eight
cycles of ice ages and warmer periods, with the end of the last ice age about 11,700 years
ago marking the beginning of the modern climate era — and of human civilization. Most of
these climate changes are attributed to very small variations in Earth’s orbit that change
the amount of solar energy our planet receives.

The current warming trend is different because it is clearly the result of
human activities since the mid-1800s, and is proceeding at a rate not seen over
many recent millennia.1 It is undeniable that human activities have produced the atmospheric
gases that have trapped more of the Sun’s energy in the Earth system. This extra energy has warmed
the atmosphere, ocean, and land, and widespread and rapid changes in the atmosphere, ocean, cryosphere,
and biosphere have occurred.

Ice cores drawn from Greenland, Antarctica, and tropical mountain
glaciers show that Earth’s climate responds to changes in greenhouse gas
levels. Ancient evidence can also be found in tree rings, ocean sediments,
coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that
current warming is occurring roughly 10 times faster than the average rate of warming after an ice age.
Carbon dioxide from human activities is increasing about 250 times faster than it did from natural
sources after the last Ice Age.

Do scientists agree on climate change?

Earth-orbiting satellites and new technologies
have helped scientists see the big picture, collecting many different types of information
about our planet and its climate all over the world. These data, collected over many years,
reveal the signs and patterns of a changing climate.

Scientists demonstrated the heat-trapping nature of carbon dioxide and other gases in the mid-19th
century.2 Many of the science instruments NASA uses to study our climate focus on how these gases
affect the movement of infrared radiation through the atmosphere. From the measured impacts of
increases in these gases, there is no question that increased greenhouse gas levels warm Earth in
response.

The Evidence for Rapid Climate Change Is Compelling:

Global Temperature Is Rising
The planet's average surface temperature has risen about degrees Fahrenheit (1 degrees Celsius)
since the late 19th century, a change driven largely by increased carbon dioxide emissions into
the atmosphere and other human activities.4 Most of the warming occurred in the past 40 years,
with the seven most recent years being the warmest. The years 2016 and 2020 are tied for the
warmest year on record.

The Ocean Is Getting Warmer
The ocean has absorbed much of this increased heat,
with the top 100 meters (about 328 feet) of ocean showing warming of 0.67 degrees Fahrenheit
(0.33 degrees Celsius) since 1969.6 Earth stores 90% of the extra energy
in the ocean.

Glaciers Are Retreating
Glaciers are retreating almost everywhere around the world —
including in the Alps, Himalayas, Andes, Rockies, Alaska,
and Africa.

The Ice Sheets Are Shrinking
The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery
and Climate Experiment show Greenland lost an average of 279 billion tons of ice per year between
1993 and 2019, while Antarctica lost about 148 billion tons of ice per year.7 Image: The Antarctic Peninsula, Credit: NASA

Snow Cover Is Decreasing
Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has
decreased over the past five decades and the snow is melting earlier

Sea Level Is Rising
Global sea level rose about 8 inches (20 centimeters) in the last century.
The rate in the last two decades, however, is nearly double that of the last century and accelerating slightly every year

Arctic Sea Ice Is Declining
Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.

Extreme Events Are Increasing in Frequency
The number of record high temperature events in the United States has been increasing,
while the number of record low temperature events has been decreasing, since 1950.
The U.S. has also witnessed increasing numbers of intense rainfall events.

Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has
increased by about 30%.13,14 This increase is due to humans emitting more
carbon dioxide into the atmosphere and hence more being absorbed into the ocean.
The ocean has absorbed between 20% and 30% of total anthropogenic carbon dioxide emissions
in recent decades (7.2 to 10.8 billion metric tons per year).

Solimões and Negro Rivers
The largest river on the planet, the Amazon, forms from the confluence of the
Solimões (the upper Amazon River) and the Negro at the Brazilian city of Manaus in central Amazonas.
At the river conjunction, the muddy, tan-colored waters of the Solimões meet the “black” water of
the Negro River. The unique mixing zone where the waters meet extends downstream through the rainforest
for hundreds of miles, and attracts tourists from all over the world, which has contributed to substantial
growth in the city of Manaus.

It is the vast quantity of sediment eroded from the Andes Mountains that gives
the Solimões its tan color. By comparison, water in the Negro derives from the
low jungles where reduced physical erosion of rock precludes mud entering the river.
In place of sediment, organic matter from the forest floor stains the river the color of black tea.

The Solimões provides nutrient-rich mud to lakes on the floodplain (lower right).
The ecology of muddy lakes differs correspondingly from that of nutrient-poor,
blackwater rivers and lakes. Solimões water can be seen leaking into the Negro west of the main
meeting zone (lower left). The Solimões is much shallower than the Negro because it has
filled its valley and bed with great quantities of sediment since the valleys were excavated.

NASA is an expert in climate and Earth science. While its role is not to set climate policy or prescribe particular responses or solutions to climate change, its job does include providing the scientific data needed to understand climate change. NASA then makes this information available to the global community – the public, policy-, and decision-makers and scientific and planning agencies around the world. (For more information, see NASA's role.)

With that said, NASA takes sustainability very seriously. NASA’s sustainability policy is to execute its mission as efficiently as possible. In doing so, we continually improve our space and ground operations.

Sustainability involves taking action now to protect the environment for both current and future living conditions. In implementing sustainability practices, NASA supports its missions by reducing risks to the environment and our communities.

In executing its mission, NASA's sustainability objectives are to:

increase energy efficiency;

increase the use of renewable energy;

measure, report, and reduce NASA's direct and indirect greenhouse gas emissions;

conserve and protect water resources through efficiency, reuse, and stormwater management;

eliminate waste, prevent pollution, and increase recycling;

leverage agency acquisitions to foster markets for sustainable technologies and environmentally preferable materials, products, and services;

design, construct, maintain, and operate high-performance sustainable buildings;

utilize power management options and reduce the number of agency data centers;

support economic growth and livability of the communities where NASA conducts business;
evaluate agency climate change risks and vulnerabilities and develop mitigation and
adaptation measures to manage both the short-and long-term effects of climate change on the agency's mission and operations;

raise employee awareness and encourage each individual in the NASA community to apply
 ]the concepts of sustainability to every aspect of their daily work to achieve these goals;

maintain compliance with all applicable federal, state, local or territorial law and regulations related to energy security, a
healthy environment, and environmentally-sound operations;
and comply with internal NASA requirements and agreements with other entities.

One of the wettest wet seasons in northern Australia transformed

large areas of the country’s desert landscape over the course of many months in 2023. A string
of major rainfall events that dropped 690 millimeters (27 inches) between October 2022 and
April 2023 made it the sixth-wettest season on record since 1900–1901.This series of false-color
images illustrates the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water
appears in shades of blue, vegetation is green, and bare land is brown. The images were acquired

by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between
January and July 2023.In the January 22 image (left), water was coursing through seasonally
dry channels of the Georgina River and Eyre Creek following weeks of heavy rains in northern
Queensland. By April 21 (middle), floodwaters had reached further downstream after another
intense period of precipitation in March. This scene shows that water had filled in some of

the north-northwest trending ridges that are part of a vast fossil landscape of wind-formed
dunes, while vegetation had emerged in wet soil upstream. Then by July 26 (right), the riverbed
had filled with even more vegetation.The Georgina River and Eyre Creek drain approximately
210,000 square kilometers (81,000 square miles), nearly the area of the United Kingdom. Visible
in the lower part of the images, the lake gets refreshed about every three years; when it

reaches especially high levels, it may take 18 months to 2 years to dry up. Two smaller neighboring
lakes flood seasonally. These three lakes and surrounding floodplains support hundreds of
thousands of waterbirds and are designated as an Important Bird Area.Seasonal flooding is
a regular occurrence in these desert river systems. However, the events of the 2022-2023 rainy
season stood out in several ways. They occurred while La Niña conditions were in place over

the tropical Pacific Ocean. (The wettest seasons in northern Australia have all occurred during
La Niña years, according to Australia’s Bureau of Meteorology.) In addition, major rains occurring
in succession, as was the case with the January and March events, have the overall effect
of prolonging floods. That’s because vegetation that grows after the first event slows down
the pulse of water that comes through in the next rain event.The high water has affected both

local communities and ecosystems. Floods have inundated cattle farms and isolated towns on
temporary islands. At the same time, they are a natural feature of the “boom-and-bust” ecology
of Channel Country, providing habitat and nutrients that support biodiversity.NASA Earth Observatory
image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by
Lindsey Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves

of new growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day
Land Water View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave
a crushing amount of water toward the shore and onto unlucky surfers. Image of the Day Water
Waves of heavy rainfall left towns and farmland under water in October 2022. Image of the
Day Water Floods Acquired February 26, 2011, and February 5, 2011, these false-color images

show the impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods
January 22 - July 26, 2023JPEGOne of the wettest wet seasons in northern Australia transformed
large areas of the country’s desert landscape over the course of many months in 2023. A string
of major rainfall events that dropped 690 millimeters (27 inches) between October 2022 and
April 2023 made it the sixth-wettest season on record since 1900–1901.This series of false-color

images illustrates the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water
appears in shades of blue, vegetation is green, and bare land is brown. The images were acquired
by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between
January and July 2023.In the January 22 image (left), water was coursing through seasonally
dry channels of the Georgina River and Eyre Creek following weeks of heavy rains in northern

Queensland. By April 21 (middle), floodwaters had reached further downstream after another
intense period of precipitation in March. This scene shows that water had filled in some of
the north-northwest trending ridges that are part of a vast fossil landscape of wind-formed
dunes, while vegetation had emerged in wet soil upstream. Then by July 26 (right), the riverbed
had filled with even more vegetation.The Georgina River and Eyre Creek drain approximately

210,000 square kilometers (81,000 square miles), nearly the area of the United Kingdom. Visible
in the lower part of the images, the lake gets refreshed about every three years; when it
reaches especially high levels, it may take 18 months to 2 years to dry up. Two smaller neighboring
lakes flood seasonally. These three lakes and surrounding floodplains support hundreds of
thousands of waterbirds and are designated as an Important Bird Area.Seasonal flooding is

a regular occurrence in these desert river systems. However, the events of the 2022-2023 rainy
season stood out in several ways. They occurred while La Niña conditions were in place over
the tropical Pacific Ocean. (The wettest seasons in northern Australia have all occurred during
La Niña years, according to Australia’s Bureau of Meteorology.) In addition, major rains occurring
in succession, as was the case with the January and March events, have the overall effect

of prolonging floods. That’s because vegetation that grows after the first event slows down
the pulse of water that comes through in the next rain event.The high water has affected both
local communities and ecosystems. Floods have inundated cattle farms and isolated towns on
temporary islands. At the same time, they are a natural feature of the “boom-and-bust” ecology
of Channel Country, providing habitat and nutrients that support biodiversity.NASA Earth Observatory

image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by
Lindsey Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves
of new growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day
Land Water View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave
a crushing amount of water toward the shore and onto unlucky surfers. Image of the Day Water

Waves of heavy rainfall left towns and farmland under water in October 2022. Image of the
Day Water Floods Acquired February 26, 2011, and February 5, 2011, these false-color images
show the impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods
August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated

cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams

along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks

of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the

storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers

out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours

in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence January 22 - July 26, 2023JPEGOne of the wettest wet seasons in northern Australia
transformed large areas of the country’s desert landscape over the course of many months in
2023. A string of major rainfall events that dropped 690 millimeters (27 inches) between October
2022 and April 2023 made it the sixth-wettest season on record since 1900–1901.This series

of false-color images illustrates the rainfall’s months-long effects downstream in the Lake
Eyre Basin. Water appears in shades of blue, vegetation is green, and bare land is brown.
The images were acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s
Terra satellite between January and July 2023.In the January 22 image (left), water was coursing
through seasonally dry channels of the Georgina River and Eyre Creek following weeks of heavy

rains in northern Queensland. By April 21 (middle), floodwaters had reached further downstream
after another intense period of precipitation in March. This scene shows that water had filled
in some of the north-northwest trending ridges that are part of a vast fossil landscape of
wind-formed dunes, while vegetation had emerged in wet soil upstream. Then by July 26 (right),
the riverbed had filled with even more vegetation.The Georgina River and Eyre Creek drain

approximately 210,000 square kilometers (81,000 square miles), nearly the area of the United
Kingdom. Visible in the lower part of the images, the lake gets refreshed about every three
years; when it reaches especially high levels, it may take 18 months to 2 years to dry up.
Two smaller neighboring lakes flood seasonally. These three lakes and surrounding floodplains
support hundreds of thousands of waterbirds and are designated as an Important Bird Area.Seasonal

flooding is a regular occurrence in these desert river systems. However, the events of the
2022-2023 rainy season stood out in several ways. They occurred while La Niña conditions were
in place over the tropical Pacific Ocean. (The wettest seasons in northern Australia have
all occurred during La Niña years, according to Australia’s Bureau of Meteorology.) In addition,
major rains occurring in succession, as was the case with the January and March events, have

the overall effect of prolonging floods. That’s because vegetation that grows after the first
event slows down the pulse of water that comes through in the next rain event.The high water
has affected both local communities and ecosystems. Floods have inundated cattle farms and
isolated towns on temporary islands. At the same time, they are a natural feature of the “boom-and-bust”
ecology of Channel Country, providing habitat and nutrients that support biodiversity.NASA

Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set
off waves of new growth across Channel Country.Image of the Day for August 7, 2023 Image of
the Day Land Water View more Images of the Day: Floods The waves off the coast of Teahupo’o
can heave a crushing amount of water toward the shore and onto unlucky surfers. Image of the

Day Water Waves of heavy rainfall left towns and farmland under water in October 2022. Image
of the Day Water Floods Acquired February 26, 2011, and February 5, 2011, these false-color
images show the impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land
Floods August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25,
2023JPEGSeptember 18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean

inundated cities along the northeastern coast of Libya in early September 2023, causing thousands
of deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams

along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks

of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the

storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers

out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours

in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational

to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color

data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in

the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.

However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered

in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability

in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from

materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean

color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the

diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level

measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence January 22 - July 26,
2023JPEGOne of the wettest wet seasons in northern Australia transformed large areas of the
country’s desert landscape over the course of many months in 2023. A string of major rainfall

events that dropped 690 millimeters (27 inches) between October 2022 and April 2023 made it
the sixth-wettest season on record since 1900–1901.This series of false-color images illustrates
the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water appears in shades
of blue, vegetation is green, and bare land is brown. The images were acquired by the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between January and

July 2023.In the January 22 image (left), water was coursing through seasonally dry channels
of the Georgina River and Eyre Creek following weeks of heavy rains in northern Queensland.
By April 21 (middle), floodwaters had reached further downstream after another intense period
of precipitation in March. This scene shows that water had filled in some of the north-northwest
trending ridges that are part of a vast fossil landscape of wind-formed dunes, while vegetation

had emerged in wet soil upstream. Then by July 26 (right), the riverbed had filled with even
more vegetation.The Georgina River and Eyre Creek drain approximately 210,000 square kilometers
(81,000 square miles), nearly the area of the United Kingdom. Visible in the lower part of
the images, the lake gets refreshed about every three years; when it reaches especially high
levels, it may take 18 months to 2 years to dry up. Two smaller neighboring lakes flood seasonally.

These three lakes and surrounding floodplains support hundreds of thousands of waterbirds
and are designated as an Important Bird Area.Seasonal flooding is a regular occurrence in
these desert river systems. However, the events of the 2022-2023 rainy season stood out in
several ways. They occurred while La Niña conditions were in place over the tropical Pacific
Ocean. (The wettest seasons in northern Australia have all occurred during La Niña years,

according to Australia’s Bureau of Meteorology.) In addition, major rains occurring in succession,
as was the case with the January and March events, have the overall effect of prolonging floods.
That’s because vegetation that grows after the first event slows down the pulse of water that
comes through in the next rain event.The high water has affected both local communities and
ecosystems. Floods have inundated cattle farms and isolated towns on temporary islands. At

the same time, they are a natural feature of the “boom-and-bust” ecology of Channel Country,
providing habitat and nutrients that support biodiversity.NASA Earth Observatory image by
Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey
Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves of new
growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day Land Water

View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave a crushing
amount of water toward the shore and onto unlucky surfers. Image of the Day Water Waves of
heavy rainfall left towns and farmland under water in October 2022. Image of the Day Water
Floods Acquired February 26, 2011, and February 5, 2011, these false-color images show the
impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods August

25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over

100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.

The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate

that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest

in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023

Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm

dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color

of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the

U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with

darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s

surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the

remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had

been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,

the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming

climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)

satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image

of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe

Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities

issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks

disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely

a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite

sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility

was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary

Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze January 22
- July 26, 2023JPEGOne of the wettest wet seasons in northern Australia transformed large
areas of the country’s desert landscape over the course of many months in 2023. A string of

major rainfall events that dropped 690 millimeters (27 inches) between October 2022 and April
2023 made it the sixth-wettest season on record since 1900–1901.This series of false-color
images illustrates the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water
appears in shades of blue, vegetation is green, and bare land is brown. The images were acquired
by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between

January and July 2023.In the January 22 image (left), water was coursing through seasonally
dry channels of the Georgina River and Eyre Creek following weeks of heavy rains in northern
Queensland. By April 21 (middle), floodwaters had reached further downstream after another
intense period of precipitation in March. This scene shows that water had filled in some of
the north-northwest trending ridges that are part of a vast fossil landscape of wind-formed

dunes, while vegetation had emerged in wet soil upstream. Then by July 26 (right), the riverbed
had filled with even more vegetation.The Georgina River and Eyre Creek drain approximately
210,000 square kilometers (81,000 square miles), nearly the area of the United Kingdom. Visible
in the lower part of the images, the lake gets refreshed about every three years; when it
reaches especially high levels, it may take 18 months to 2 years to dry up. Two smaller neighboring

lakes flood seasonally. These three lakes and surrounding floodplains support hundreds of
thousands of waterbirds and are designated as an Important Bird Area.Seasonal flooding is
a regular occurrence in these desert river systems. However, the events of the 2022-2023 rainy
season stood out in several ways. They occurred while La Niña conditions were in place over
the tropical Pacific Ocean. (The wettest seasons in northern Australia have all occurred during

La Niña years, according to Australia’s Bureau of Meteorology.) In addition, major rains occurring
in succession, as was the case with the January and March events, have the overall effect
of prolonging floods. That’s because vegetation that grows after the first event slows down
the pulse of water that comes through in the next rain event.The high water has affected both
local communities and ecosystems. Floods have inundated cattle farms and isolated towns on

temporary islands. At the same time, they are a natural feature of the “boom-and-bust” ecology
of Channel Country, providing habitat and nutrients that support biodiversity.NASA Earth Observatory
image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by
Lindsey Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves
of new growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day

Land Water View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave
a crushing amount of water toward the shore and onto unlucky surfers. Image of the Day Water
Waves of heavy rainfall left towns and farmland under water in October 2022. Image of the
Day Water Floods Acquired February 26, 2011, and February 5, 2011, these false-color images
show the impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods

August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over

100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.

The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate

that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest

in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023

Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm

dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color

of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the

U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with

darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s

surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the

remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had

been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,

the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming

climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)

satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image

of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe

Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities

issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks

disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely

a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite

sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility

was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary

Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,

making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and

hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area

between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story

by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings

colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth

Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere

Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice January 22 - July 26, 2023JPEGOne

of the wettest wet seasons in northern Australia transformed large areas of the country’s
desert landscape over the course of many months in 2023. A string of major rainfall events
that dropped 690 millimeters (27 inches) between October 2022 and April 2023 made it the sixth-wettest
season on record since 1900–1901.This series of false-color images illustrates the rainfall’s
months-long effects downstream in the Lake Eyre Basin. Water appears in shades of blue, vegetation

is green, and bare land is brown. The images were acquired by the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASA’s Terra satellite between January and July 2023.In the January
22 image (left), water was coursing through seasonally dry channels of the Georgina River
and Eyre Creek following weeks of heavy rains in northern Queensland. By April 21 (middle),
floodwaters had reached further downstream after another intense period of precipitation in

March. This scene shows that water had filled in some of the north-northwest trending ridges
that are part of a vast fossil landscape of wind-formed dunes, while vegetation had emerged
in wet soil upstream. Then by July 26 (right), the riverbed had filled with even more vegetation.The
Georgina River and Eyre Creek drain approximately 210,000 square kilometers (81,000 square
miles), nearly the area of the United Kingdom. Visible in the lower part of the images, the

lake gets refreshed about every three years; when it reaches especially high levels, it may
take 18 months to 2 years to dry up. Two smaller neighboring lakes flood seasonally. These
three lakes and surrounding floodplains support hundreds of thousands of waterbirds and are
designated as an Important Bird Area.Seasonal flooding is a regular occurrence in these desert
river systems. However, the events of the 2022-2023 rainy season stood out in several ways.

They occurred while La Niña conditions were in place over the tropical Pacific Ocean. (The
wettest seasons in northern Australia have all occurred during La Niña years, according to
Australia’s Bureau of Meteorology.) In addition, major rains occurring in succession, as was
the case with the January and March events, have the overall effect of prolonging floods.
That’s because vegetation that grows after the first event slows down the pulse of water that

comes through in the next rain event.The high water has affected both local communities and
ecosystems. Floods have inundated cattle farms and isolated towns on temporary islands. At
the same time, they are a natural feature of the “boom-and-bust” ecology of Channel Country,
providing habitat and nutrients that support biodiversity.NASA Earth Observatory image by
Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey

Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves of new
growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day Land Water
View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave a crushing
amount of water toward the shore and onto unlucky surfers. Image of the Day Water Waves of
heavy rainfall left towns and farmland under water in October 2022. Image of the Day Water

Floods Acquired February 26, 2011, and February 5, 2011, these false-color images show the
impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods August
25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of

deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland

of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier

than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,

or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological

Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s

coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods

Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected

under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua

satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher

latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown

in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color

information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating

all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough

to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there

is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory

image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image

of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke

is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,

a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,

dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.

A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena

visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands

become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour

funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts

of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the

northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone

contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts

allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported

by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,

2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and

an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters

(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.

Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,

as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how

long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from

the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land

Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for

their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and

operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life January 22 - July
26, 2023JPEGOne of the wettest wet seasons in northern Australia transformed large areas of
the country’s desert landscape over the course of many months in 2023. A string of major rainfall
events that dropped 690 millimeters (27 inches) between October 2022 and April 2023 made it

the sixth-wettest season on record since 1900–1901.This series of false-color images illustrates
the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water appears in shades
of blue, vegetation is green, and bare land is brown. The images were acquired by the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between January and
July 2023.In the January 22 image (left), water was coursing through seasonally dry channels

of the Georgina River and Eyre Creek following weeks of heavy rains in northern Queensland.
By April 21 (middle), floodwaters had reached further downstream after another intense period
of precipitation in March. This scene shows that water had filled in some of the north-northwest
trending ridges that are part of a vast fossil landscape of wind-formed dunes, while vegetation
had emerged in wet soil upstream. Then by July 26 (right), the riverbed had filled with even

more vegetation.The Georgina River and Eyre Creek drain approximately 210,000 square kilometers
(81,000 square miles), nearly the area of the United Kingdom. Visible in the lower part of
the images, the lake gets refreshed about every three years; when it reaches especially high
levels, it may take 18 months to 2 years to dry up. Two smaller neighboring lakes flood seasonally.
These three lakes and surrounding floodplains support hundreds of thousands of waterbirds

and are designated as an Important Bird Area.Seasonal flooding is a regular occurrence in
these desert river systems. However, the events of the 2022-2023 rainy season stood out in
several ways. They occurred while La Niña conditions were in place over the tropical Pacific
Ocean. (The wettest seasons in northern Australia have all occurred during La Niña years,
according to Australia’s Bureau of Meteorology.) In addition, major rains occurring in succession,

as was the case with the January and March events, have the overall effect of prolonging floods.
That’s because vegetation that grows after the first event slows down the pulse of water that
comes through in the next rain event.The high water has affected both local communities and
ecosystems. Floods have inundated cattle farms and isolated towns on temporary islands. At
the same time, they are a natural feature of the “boom-and-bust” ecology of Channel Country,

providing habitat and nutrients that support biodiversity.NASA Earth Observatory image by
Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey
Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves of new
growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day Land Water
View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave a crushing

amount of water toward the shore and onto unlucky surfers. Image of the Day Water Waves of
heavy rainfall left towns and farmland under water in October 2022. Image of the Day Water
Floods Acquired February 26, 2011, and February 5, 2011, these false-color images show the
impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods August
25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember

18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow

valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired

by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International

Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution

estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting

of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.

Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,

microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has

undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).

By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been

the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far

exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data

to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital

particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.

This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The

new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets

from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate

Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s

spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert

was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined

from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA

Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human

Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land

The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,

the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach

to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during

this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,

and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area

between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story

by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve

off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going

dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters
(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered

about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.
Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the

landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,
as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,

the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how
long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can

fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from
the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View

more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land
Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence

Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for
their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.

Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and
operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember
10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember

10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer
and early fall of 2023. In September, low water levels limited barge shipments downriver and
threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the
Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021

(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This
is the second year in a row drought has caused the river to fall to near-record lows at many
gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That
was the lowest level recorded there since the start of National Weather Service records in

1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they
are measured with respect to a chosen reference point. That is why some gauge height measurements
are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally
decline in the fall and winter, and in 2022, the river did not get that low until mid-October.

September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in
2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.
In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department
of Agriculture, the National Oceanic and Atmospheric Administration, and the University of

Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts
drought intensity in progressive shades of orange to red. It is based on an analysis of climate,
soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring
effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.

Lack of precipitation and high temperatures over several months severely dried out soils in
states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of
soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions
along the river interrupted normal shipments of goods. According to the Associated Press,

barge companies reduced the weight carried in many shipments in September because the river
was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported
down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the
Gulf of Mexico has also allowed saltwater to make its way up the river and into some water

treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines
Parish are under drinking water advisories and have relied on bottled water for cooking and
drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast
Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late

October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren
Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States
Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the
river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023

Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect
water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily
passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests
in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record

keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low
water levels are making it difficult to ship goods down the river and allowing a wedge of
saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing January
22 - July 26, 2023JPEGOne of the wettest wet seasons in northern Australia transformed large
areas of the country’s desert landscape over the course of many months in 2023. A string of

major rainfall events that dropped 690 millimeters (27 inches) between October 2022 and April
2023 made it the sixth-wettest season on record since 1900–1901.This series of false-color
images illustrates the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water
appears in shades of blue, vegetation is green, and bare land is brown. The images were acquired
by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between

January and July 2023.In the January 22 image (left), water was coursing through seasonally
dry channels of the Georgina River and Eyre Creek following weeks of heavy rains in northern
Queensland. By April 21 (middle), floodwaters had reached further downstream after another
intense period of precipitation in March. This scene shows that water had filled in some of
the north-northwest trending ridges that are part of a vast fossil landscape of wind-formed

dunes, while vegetation had emerged in wet soil upstream. Then by July 26 (right), the riverbed
had filled with even more vegetation.The Georgina River and Eyre Creek drain approximately
210,000 square kilometers (81,000 square miles), nearly the area of the United Kingdom. Visible
in the lower part of the images, the lake gets refreshed about every three years; when it
reaches especially high levels, it may take 18 months to 2 years to dry up. Two smaller neighboring

lakes flood seasonally. These three lakes and surrounding floodplains support hundreds of
thousands of waterbirds and are designated as an Important Bird Area.Seasonal flooding is
a regular occurrence in these desert river systems. However, the events of the 2022-2023 rainy
season stood out in several ways. They occurred while La Niña conditions were in place over
the tropical Pacific Ocean. (The wettest seasons in northern Australia have all occurred during

La Niña years, according to Australia’s Bureau of Meteorology.) In addition, major rains occurring
in succession, as was the case with the January and March events, have the overall effect
of prolonging floods. That’s because vegetation that grows after the first event slows down
the pulse of water that comes through in the next rain event.The high water has affected both
local communities and ecosystems. Floods have inundated cattle farms and isolated towns on

temporary islands. At the same time, they are a natural feature of the “boom-and-bust” ecology
of Channel Country, providing habitat and nutrients that support biodiversity.NASA Earth Observatory
image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by
Lindsey Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves
of new growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day

Land Water View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave
a crushing amount of water toward the shore and onto unlucky surfers. Image of the Day Water
Waves of heavy rainfall left towns and farmland under water in October 2022. Image of the
Day Water Floods Acquired February 26, 2011, and February 5, 2011, these false-color images
show the impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods

August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over

100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.

The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate

that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest

in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023

Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm

dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color

of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the

U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with

darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s

surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the

remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had

been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,

the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming

climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)

satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image

of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe

Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities

issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks

disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely

a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite

sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility

was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary

Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,

making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and

hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area

between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story

by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings

colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth

Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere

Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay

18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters
(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2

(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.
Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University

of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,
as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,

according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how
long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome

interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from
the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start

pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land
Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists

could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for
their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late

1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and
operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember

10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer
and early fall of 2023. In September, low water levels limited barge shipments downriver and
threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the

Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This
is the second year in a row drought has caused the river to fall to near-record lows at many
gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That

was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they
are measured with respect to a chosen reference point. That is why some gauge height measurements
are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally

decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in
2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.
In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department

of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts
drought intensity in progressive shades of orange to red. It is based on an analysis of climate,
soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring

effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in
states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of
soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions

along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river
was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported
down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the

Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines
Parish are under drinking water advisories and have relied on bottled water for cooking and
drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast

Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren
Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States
Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the

river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect
water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily
passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests

in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low
water levels are making it difficult to ship goods down the river and allowing a wedge of
saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced

algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long
lake has a watershed that spans one million square kilometers (386,000 square miles), draining
some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September

25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated
that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of
the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients

like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm
the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that
can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents

and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer
months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels
were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between

1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous
to the lake were increased agricultural activities in the watershed and a higher frequency
of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019

study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a
measure of phytoplankton biomass, were on average more than twice as high in the south basin,
compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx

of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View
more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are
sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface

of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the
Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount
St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water

Human Presence Remote Sensing January 22 - July 26, 2023JPEGOne of the wettest wet seasons
in northern Australia transformed large areas of the country’s desert landscape over the course
of many months in 2023. A string of major rainfall events that dropped 690 millimeters (27
inches) between October 2022 and April 2023 made it the sixth-wettest season on record since
1900–1901.This series of false-color images illustrates the rainfall’s months-long effects

downstream in the Lake Eyre Basin. Water appears in shades of blue, vegetation is green, and
bare land is brown. The images were acquired by the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite between January and July 2023.In the January 22 image (left),
water was coursing through seasonally dry channels of the Georgina River and Eyre Creek following
weeks of heavy rains in northern Queensland. By April 21 (middle), floodwaters had reached

further downstream after another intense period of precipitation in March. This scene shows
that water had filled in some of the north-northwest trending ridges that are part of a vast
fossil landscape of wind-formed dunes, while vegetation had emerged in wet soil upstream.
Then by July 26 (right), the riverbed had filled with even more vegetation.The Georgina River
and Eyre Creek drain approximately 210,000 square kilometers (81,000 square miles), nearly

the area of the United Kingdom. Visible in the lower part of the images, the lake gets refreshed
about every three years; when it reaches especially high levels, it may take 18 months to
2 years to dry up. Two smaller neighboring lakes flood seasonally. These three lakes and surrounding
floodplains support hundreds of thousands of waterbirds and are designated as an Important
Bird Area.Seasonal flooding is a regular occurrence in these desert river systems. However,

the events of the 2022-2023 rainy season stood out in several ways. They occurred while La
Niña conditions were in place over the tropical Pacific Ocean. (The wettest seasons in northern
Australia have all occurred during La Niña years, according to Australia’s Bureau of Meteorology.)
In addition, major rains occurring in succession, as was the case with the January and March
events, have the overall effect of prolonging floods. That’s because vegetation that grows

after the first event slows down the pulse of water that comes through in the next rain event.The
high water has affected both local communities and ecosystems. Floods have inundated cattle
farms and isolated towns on temporary islands. At the same time, they are a natural feature
of the “boom-and-bust” ecology of Channel Country, providing habitat and nutrients that support
biodiversity.NASA Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS

LANCE and GIBS/Worldview. Story by Lindsey Doermann.View this area in EO ExplorerRepeated
heavy rains in Australia set off waves of new growth across Channel Country.Image of the Day
for August 7, 2023 Image of the Day Land Water View more Images of the Day: Floods The waves
off the coast of Teahupo’o can heave a crushing amount of water toward the shore and onto
unlucky surfers. Image of the Day Water Waves of heavy rainfall left towns and farmland under

water in October 2022. Image of the Day Water Floods Acquired February 26, 2011, and February
5, 2011, these false-color images show the impact of heavy rains in marshy areas southeast
of Georgetown, Guyana. Land Floods August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September
18, 2023August 25, 2023JPEGSeptember 18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone
in the Mediterranean inundated cities along the northeastern coast of Libya in early September

2023, causing thousands of deaths. The port city of Derna (Darnah), home to about 90,000 people,
was one of the worst hit by the storm and suffered extensive flooding and damage. On September
10 and 11, over 100 millimeters (4 inches) of rain fell on Derna. The city lies at the end
of a long, narrow valley, called a wadi, which is dry except during the rainy season. Floods
triggered two dams along the wadi to collapse. The failure of the second dam, located just

one kilometer inland of Derna, unleashed 3- to 7-meter-high floodwater that tore through the
city. According to news reports, the flash floods destroyed roads and swept entire neighborhoods
out to sea. The images above show the city before and after the storm. The image on the right,
acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded
banks of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears

muddier than in the image on the left, which shows the same area on August 25 and was acquired
by Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,

or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological

Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s

coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods

Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected

under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua

satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher

latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown

in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color

information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating

all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough

to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there

is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory

image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image

of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke

is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,

a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,

dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.

A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena

visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands

become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour

funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts

of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the

northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone

contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts

allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported

by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,

2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and

an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters

(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.

Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,

as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how

long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from

the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land

Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for

their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and

operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember
10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer
and early fall of 2023. In September, low water levels limited barge shipments downriver and

threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the
Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This
is the second year in a row drought has caused the river to fall to near-record lows at many

gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That
was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they
are measured with respect to a chosen reference point. That is why some gauge height measurements

are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally
decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in
2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.

In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department
of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts
drought intensity in progressive shades of orange to red. It is based on an analysis of climate,

soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring
effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in
states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of

soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions
along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river
was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported

down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the
Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines
Parish are under drinking water advisories and have relied on bottled water for cooking and

drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast
Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren
Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States

Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the
river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect
water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily

passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests
in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low
water levels are making it difficult to ship goods down the river and allowing a wedge of

saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced
algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long
lake has a watershed that spans one million square kilometers (386,000 square miles), draining

some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September
25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated
that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of

the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients
like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm
the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that

can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents
and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer
months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels

were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between
1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous
to the lake were increased agricultural activities in the watershed and a higher frequency

of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019
study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a
measure of phytoplankton biomass, were on average more than twice as high in the south basin,

compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx
of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View
more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are

sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface
of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the
Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount

St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water
Human Presence Remote Sensing October 8, 2022JPEGOctober 3, 2023JPEGOctober 8, 2022October
3, 2023October 8, 2022JPEGOctober 3, 2023JPEGOctober 3, 2023JPEGJuly through October fall
within the dry season in the western and northern Amazon rainforest, but a particularly acute

lack of rain during this period in 2023 has pushed the region into a severe drought.The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image (right) of the parched
Rio Negro in the Brazilian province of Amazonas near the city of Manaus on October 3, 2023.
On that date, the level of the river, the largest tributary of the Amazon River, had dropped
to 15.14 meters (50.52 feet), according to data collected by the Port of Manaus. For comparison,

the image on the left shows the same area on October 8, 2022, when the water level was 19.59
meters, a more typical level for October. Rio Negro water levels continued to drop in the
days after the image was collected, reaching a record low of 13.49 meters on October 17, 2023.Some
areas in the Amazon River’s watershed have received less rain between July and September than
any year since 1980, Reuters reported. The drought has been particularly severe in the Rio

Negro watershed in northern Amazonas, as well as parts of southern Venezuela and southern
Colombia.“Overall, this is a pretty unusual and extreme situation,” said René Garreaud, an
atmospheric scientist at the University of Chile. “The primary culprit exacerbating the drought
appears to be El Niño.” This cyclical warming of surface waters in the central-eastern Pacific
functions somewhat like a boulder in the middle of a stream, disrupting atmospheric circulation

patterns in ways that lead to wetter conditions over the equatorial Pacific and drier conditions
over the Amazon Basin.According to news outlets, the low river water levels on the Rio Negro
and other nearby rivers have disrupted drinking water supplies in hundreds of communities,
slowed commercial navigation, and led to fish and dolphin die-offs.Manaus, the capital and
largest city of the Brazilian state of Amazonas, is the primary transportation hub for the

upper Amazon, serving as an important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include chemical, ship, and electrical
equipment manufacturing.NASA Earth Observatory images by Wanmei Liang, using Landsat data
from the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe water
level of the largest tributary of the Amazon River has hit a record low.Image of the Day for

October 18, 2023 Image of the Day Water Human Presence View more Images of the Day:The impact
of severe drought on the Negro River, a tributary of the Amazon River, and other rivers in
the basin is dramatically evident in this pair of images, which show that every body of water
has shrunk in 2010 compared to 2008. Image of the Day Atmosphere Land The volume of water
in New Mexico’s largest reservoir has dropped to historic lows due to drought and persistent

demand. Image of the Day Water Human Presence Acquired June 25, 2011, and June 22, 2010, these
false-color images compare conditions along the Souris River, which reached a historic crest
at Minot, North Dakota in June 2011. Land Floods Acquired May 11, 2011, and April 21, 2007,
these false-color images show the Mississippi River near Natchez, Mississippi. The image from
May 2011 shows flooded conditions. Land Floods January 22 - July 26, 2023JPEGOne of the wettest

wet seasons in northern Australia transformed large areas of the country’s desert landscape
over the course of many months in 2023. A string of major rainfall events that dropped 690
millimeters (27 inches) between October 2022 and April 2023 made it the sixth-wettest season
on record since 1900–1901.This series of false-color images illustrates the rainfall’s months-long
effects downstream in the Lake Eyre Basin. Water appears in shades of blue, vegetation is

green, and bare land is brown. The images were acquired by the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASA’s Terra satellite between January and July 2023.In the January
22 image (left), water was coursing through seasonally dry channels of the Georgina River
and Eyre Creek following weeks of heavy rains in northern Queensland. By April 21 (middle),
floodwaters had reached further downstream after another intense period of precipitation in

March. This scene shows that water had filled in some of the north-northwest trending ridges
that are part of a vast fossil landscape of wind-formed dunes, while vegetation had emerged
in wet soil upstream. Then by July 26 (right), the riverbed had filled with even more vegetation.The
Georgina River and Eyre Creek drain approximately 210,000 square kilometers (81,000 square
miles), nearly the area of the United Kingdom. Visible in the lower part of the images, the

lake gets refreshed about every three years; when it reaches especially high levels, it may
take 18 months to 2 years to dry up. Two smaller neighboring lakes flood seasonally. These
three lakes and surrounding floodplains support hundreds of thousands of waterbirds and are
designated as an Important Bird Area.Seasonal flooding is a regular occurrence in these desert
river systems. However, the events of the 2022-2023 rainy season stood out in several ways.

They occurred while La Niña conditions were in place over the tropical Pacific Ocean. (The
wettest seasons in northern Australia have all occurred during La Niña years, according to
Australia’s Bureau of Meteorology.) In addition, major rains occurring in succession, as was
the case with the January and March events, have the overall effect of prolonging floods.
That’s because vegetation that grows after the first event slows down the pulse of water that

comes through in the next rain event.The high water has affected both local communities and
ecosystems. Floods have inundated cattle farms and isolated towns on temporary islands. At
the same time, they are a natural feature of the “boom-and-bust” ecology of Channel Country,
providing habitat and nutrients that support biodiversity.NASA Earth Observatory image by
Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey

Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves of new
growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day Land Water
View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave a crushing
amount of water toward the shore and onto unlucky surfers. Image of the Day Water Waves of
heavy rainfall left towns and farmland under water in October 2022. Image of the Day Water

Floods Acquired February 26, 2011, and February 5, 2011, these false-color images show the
impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods August
25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated
cities along the northeastern coast of Libya in early September 2023, causing thousands of

deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams
along the wadi to collapse. The failure of the second dam, located just one kilometer inland

of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks
of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier

than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,

or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological

Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s

coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods

Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected

under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua

satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher

latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown

in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color

information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating

all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough

to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there

is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory

image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image

of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke

is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,

a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,

dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.

A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena

visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands

become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour

funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts

of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the

northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone

contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts

allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported

by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,

2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and

an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters

(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.

Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,

as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how

long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from

the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land

Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for

their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and

operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember
10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer
and early fall of 2023. In September, low water levels limited barge shipments downriver and

threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the
Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This
is the second year in a row drought has caused the river to fall to near-record lows at many

gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That
was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they
are measured with respect to a chosen reference point. That is why some gauge height measurements

are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally
decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in
2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.

In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department
of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts
drought intensity in progressive shades of orange to red. It is based on an analysis of climate,

soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring
effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in
states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of

soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions
along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river
was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported

down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the
Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines
Parish are under drinking water advisories and have relied on bottled water for cooking and

drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast
Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren
Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States

Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the
river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect
water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily

passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests
in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low
water levels are making it difficult to ship goods down the river and allowing a wedge of

saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced
algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long
lake has a watershed that spans one million square kilometers (386,000 square miles), draining

some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September
25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated
that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of

the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients
like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm
the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that

can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents
and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer
months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels

were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between
1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous
to the lake were increased agricultural activities in the watershed and a higher frequency

of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019
study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a
measure of phytoplankton biomass, were on average more than twice as high in the south basin,

compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx
of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View
more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are

sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface
of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the
Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount

St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water
Human Presence Remote Sensing October 8, 2022JPEGOctober 3, 2023JPEGOctober 8, 2022October
3, 2023October 8, 2022JPEGOctober 3, 2023JPEGOctober 3, 2023JPEGJuly through October fall
within the dry season in the western and northern Amazon rainforest, but a particularly acute

lack of rain during this period in 2023 has pushed the region into a severe drought.The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image (right) of the parched
Rio Negro in the Brazilian province of Amazonas near the city of Manaus on October 3, 2023.
On that date, the level of the river, the largest tributary of the Amazon River, had dropped
to 15.14 meters (50.52 feet), according to data collected by the Port of Manaus. For comparison,

the image on the left shows the same area on October 8, 2022, when the water level was 19.59
meters, a more typical level for October. Rio Negro water levels continued to drop in the
days after the image was collected, reaching a record low of 13.49 meters on October 17, 2023.Some
areas in the Amazon River’s watershed have received less rain between July and September than
any year since 1980, Reuters reported. The drought has been particularly severe in the Rio

Negro watershed in northern Amazonas, as well as parts of southern Venezuela and southern
Colombia.“Overall, this is a pretty unusual and extreme situation,” said René Garreaud, an
atmospheric scientist at the University of Chile. “The primary culprit exacerbating the drought
appears to be El Niño.” This cyclical warming of surface waters in the central-eastern Pacific
functions somewhat like a boulder in the middle of a stream, disrupting atmospheric circulation

patterns in ways that lead to wetter conditions over the equatorial Pacific and drier conditions
over the Amazon Basin.According to news outlets, the low river water levels on the Rio Negro
and other nearby rivers have disrupted drinking water supplies in hundreds of communities,
slowed commercial navigation, and led to fish and dolphin die-offs.Manaus, the capital and
largest city of the Brazilian state of Amazonas, is the primary transportation hub for the

upper Amazon, serving as an important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include chemical, ship, and electrical
equipment manufacturing.NASA Earth Observatory images by Wanmei Liang, using Landsat data
from the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe water
level of the largest tributary of the Amazon River has hit a record low.Image of the Day for

October 18, 2023 Image of the Day Water Human Presence View more Images of the Day:The impact
of severe drought on the Negro River, a tributary of the Amazon River, and other rivers in
the basin is dramatically evident in this pair of images, which show that every body of water
has shrunk in 2010 compared to 2008. Image of the Day Atmosphere Land The volume of water
in New Mexico’s largest reservoir has dropped to historic lows due to drought and persistent

demand. Image of the Day Water Human Presence Acquired June 25, 2011, and June 22, 2010, these
false-color images compare conditions along the Souris River, which reached a historic crest
at Minot, North Dakota in June 2011. Land Floods Acquired May 11, 2011, and April 21, 2007,
these false-color images show the Mississippi River near Natchez, Mississippi. The image from
May 2011 shows flooded conditions. Land Floods September 6, 2020JPEGSeptember 7, 2023JPEGSeptember

6, 2020September 7, 2023September 6, 2020JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter
rapidly growing in volume just a few years earlier, northwest Iran’s Lake Urmia nearly dried
out in autumn 2023. The largest lake in the Middle East and one of the largest hypersaline
lakes on Earth at its greatest extent, Lake Urmia has for the most part transformed into a
vast, dry salt flat. On September 7, 2023, the OLI-2 (Operational Land Imager-2) on Landsat

9 captured this image (right) of the desiccated lakebed. It stands in contrast to the image
from three years earlier (left), acquired by the OLI on Landsat 8 on September 8, 2020, when
water filled most of the basin and salt deposits were only visible around the perimeter of
the lake. The replenishment followed a period of above-average precipitation that sent a surge
of freshwater into the basin, expanding its watery footprint. Drier conditions have since

brought levels back down. The longer-term trend for Urmia has been one toward drying. In 1995,
Lake Urmia reached a high-water mark; then in the ensuing two decades, the lake level dropped
more than 7 meters (23 feet) and lost approximately 90 percent of its area. Consecutive droughts,
agricultural water use, and dam construction on rivers feeding the lake have contributed to
the decline. A shrinking Lake Urmia has implications for ecological and human health. The

lake, its islands, and surrounding wetlands comprise valuable habitat and are recognized as
a UNESCO Biosphere Reserve, Ramsar site, and national park. The area provides breeding grounds
for waterbirds such as flamingos, white pelicans, and white-headed ducks, as well as a stopover
for migratory species. However, with low lake levels, what water remains becomes more saline
and taxes the populations of brine shrimp and other food sources for larger animals. A shrinking

lake also increases the likelihood of dust from the exposed lakebed becoming swept up by winds
and degrading air quality. Recent studies have linked the low water levels in Lake Urmia with
respiratory health impacts among the local population.The relative effects of climate, water
usage, and dams on Lake Urmia’s water level is a topic of debate. The lake did see some recovery
during a 10-year restoration program beginning in 2013. However, the efficacy of that effort

has been difficult to parse since strong rains also fell during that period. Some research
has concluded that climatic factors were primarily responsible for the recovery. NASA Earth
Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey.
Story by Lindsey Doermann.View this area in EO ExplorerA few years after a fresh influx of
water raised its levels, the large lake has nearly gone dry.Image of the Day for October 10,

2023 Image of the Day Land Water View more Images of the Day:Water levels are at their lowest
since 1937. Image of the Day Water Drought Fires Long and short. Deep and shallow. Salty and
fresh. Blue and brown. These are Africa’s Lake Tanganyika and Lake Rukwa. Image of the Day
Land Water In May 2016, the reservoir behind Hoover Dam reached its lowest level since the
1930s. Image of the Day Water When the water gets saltier in Iran’s largest lake, the microscopic

inhabitants can turn the water dark red. Image of the Day Water Water Color January 22 - July
26, 2023JPEGOne of the wettest wet seasons in northern Australia transformed large areas of
the country’s desert landscape over the course of many months in 2023. A string of major rainfall
events that dropped 690 millimeters (27 inches) between October 2022 and April 2023 made it
the sixth-wettest season on record since 1900–1901.This series of false-color images illustrates

the rainfall’s months-long effects downstream in the Lake Eyre Basin. Water appears in shades
of blue, vegetation is green, and bare land is brown. The images were acquired by the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between January and
July 2023.In the January 22 image (left), water was coursing through seasonally dry channels
of the Georgina River and Eyre Creek following weeks of heavy rains in northern Queensland.

By April 21 (middle), floodwaters had reached further downstream after another intense period
of precipitation in March. This scene shows that water had filled in some of the north-northwest
trending ridges that are part of a vast fossil landscape of wind-formed dunes, while vegetation
had emerged in wet soil upstream. Then by July 26 (right), the riverbed had filled with even
more vegetation.The Georgina River and Eyre Creek drain approximately 210,000 square kilometers

(81,000 square miles), nearly the area of the United Kingdom. Visible in the lower part of
the images, the lake gets refreshed about every three years; when it reaches especially high
levels, it may take 18 months to 2 years to dry up. Two smaller neighboring lakes flood seasonally.
These three lakes and surrounding floodplains support hundreds of thousands of waterbirds
and are designated as an Important Bird Area.Seasonal flooding is a regular occurrence in

these desert river systems. However, the events of the 2022-2023 rainy season stood out in
several ways. They occurred while La Niña conditions were in place over the tropical Pacific
Ocean. (The wettest seasons in northern Australia have all occurred during La Niña years,
according to Australia’s Bureau of Meteorology.) In addition, major rains occurring in succession,
as was the case with the January and March events, have the overall effect of prolonging floods.

That’s because vegetation that grows after the first event slows down the pulse of water that
comes through in the next rain event.The high water has affected both local communities and
ecosystems. Floods have inundated cattle farms and isolated towns on temporary islands. At
the same time, they are a natural feature of the “boom-and-bust” ecology of Channel Country,
providing habitat and nutrients that support biodiversity.NASA Earth Observatory image by

Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey
Doermann.View this area in EO ExplorerRepeated heavy rains in Australia set off waves of new
growth across Channel Country.Image of the Day for August 7, 2023 Image of the Day Land Water
View more Images of the Day: Floods The waves off the coast of Teahupo’o can heave a crushing
amount of water toward the shore and onto unlucky surfers. Image of the Day Water Waves of

heavy rainfall left towns and farmland under water in October 2022. Image of the Day Water
Floods Acquired February 26, 2011, and February 5, 2011, these false-color images show the
impact of heavy rains in marshy areas southeast of Georgetown, Guyana. Land Floods August
25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September 18, 2023August 25, 2023JPEGSeptember
18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone in the Mediterranean inundated

cities along the northeastern coast of Libya in early September 2023, causing thousands of
deaths. The port city of Derna (Darnah), home to about 90,000 people, was one of the worst
hit by the storm and suffered extensive flooding and damage. On September 10 and 11, over
100 millimeters (4 inches) of rain fell on Derna. The city lies at the end of a long, narrow
valley, called a wadi, which is dry except during the rainy season. Floods triggered two dams

along the wadi to collapse. The failure of the second dam, located just one kilometer inland
of Derna, unleashed 3- to 7-meter-high floodwater that tore through the city. According to
news reports, the flash floods destroyed roads and swept entire neighborhoods out to sea.
The images above show the city before and after the storm. The image on the right, acquired
by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded banks

of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears muddier
than in the image on the left, which shows the same area on August 25 and was acquired by
Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the

storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers

out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours

in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational

to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color

data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in

the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.

However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered

in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability

in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from

materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean

color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the

diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level

measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage

of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires

have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced

in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton

growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.

Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution

of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran

Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa

(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts

allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported

by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach

to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during

this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast

are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust

and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling

in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters
(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other

image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.
Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use

in the nearby community of Paine, increasing water use by farmers and in homes and pools,
as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the

water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how
long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much

longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from
the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly

22 years, but groundwater levels still suffer from years of drought. Image of the Day Land
Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over

water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for
their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over

the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and
operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember
10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer

and early fall of 2023. In September, low water levels limited barge shipments downriver and
threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the
Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This

is the second year in a row drought has caused the river to fall to near-record lows at many
gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That
was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they

are measured with respect to a chosen reference point. That is why some gauge height measurements
are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally
decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in

2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.
In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department
of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts

drought intensity in progressive shades of orange to red. It is based on an analysis of climate,
soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring
effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in

states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of
soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions
along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river

was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported
down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the
Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines

Parish are under drinking water advisories and have relied on bottled water for cooking and
drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast
Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren

Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States
Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the
river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect

water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily
passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests
in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low

water levels are making it difficult to ship goods down the river and allowing a wedge of
saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced
algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long

lake has a watershed that spans one million square kilometers (386,000 square miles), draining
some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September
25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated

that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of
the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients
like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm

the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that
can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents
and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer

months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels
were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between
1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous

to the lake were increased agricultural activities in the watershed and a higher frequency
of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019
study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a

measure of phytoplankton biomass, were on average more than twice as high in the south basin,
compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx
of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View

more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are
sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface
of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the

Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount
St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water
Human Presence Remote Sensing October 8, 2022JPEGOctober 3, 2023JPEGOctober 8, 2022October
3, 2023October 8, 2022JPEGOctober 3, 2023JPEGOctober 3, 2023JPEGJuly through October fall

within the dry season in the western and northern Amazon rainforest, but a particularly acute
lack of rain during this period in 2023 has pushed the region into a severe drought.The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image (right) of the parched
Rio Negro in the Brazilian province of Amazonas near the city of Manaus on October 3, 2023.
On that date, the level of the river, the largest tributary of the Amazon River, had dropped

to 15.14 meters (50.52 feet), according to data collected by the Port of Manaus. For comparison,
the image on the left shows the same area on October 8, 2022, when the water level was 19.59
meters, a more typical level for October. Rio Negro water levels continued to drop in the
days after the image was collected, reaching a record low of 13.49 meters on October 17, 2023.Some
areas in the Amazon River’s watershed have received less rain between July and September than

any year since 1980, Reuters reported. The drought has been particularly severe in the Rio
Negro watershed in northern Amazonas, as well as parts of southern Venezuela and southern
Colombia.“Overall, this is a pretty unusual and extreme situation,” said René Garreaud, an
atmospheric scientist at the University of Chile. “The primary culprit exacerbating the drought
appears to be El Niño.” This cyclical warming of surface waters in the central-eastern Pacific

functions somewhat like a boulder in the middle of a stream, disrupting atmospheric circulation
patterns in ways that lead to wetter conditions over the equatorial Pacific and drier conditions
over the Amazon Basin.According to news outlets, the low river water levels on the Rio Negro
and other nearby rivers have disrupted drinking water supplies in hundreds of communities,
slowed commercial navigation, and led to fish and dolphin die-offs.Manaus, the capital and

largest city of the Brazilian state of Amazonas, is the primary transportation hub for the
upper Amazon, serving as an important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include chemical, ship, and electrical
equipment manufacturing.NASA Earth Observatory images by Wanmei Liang, using Landsat data
from the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe water

level of the largest tributary of the Amazon River has hit a record low.Image of the Day for
October 18, 2023 Image of the Day Water Human Presence View more Images of the Day:The impact
of severe drought on the Negro River, a tributary of the Amazon River, and other rivers in
the basin is dramatically evident in this pair of images, which show that every body of water
has shrunk in 2010 compared to 2008. Image of the Day Atmosphere Land The volume of water

in New Mexico’s largest reservoir has dropped to historic lows due to drought and persistent
demand. Image of the Day Water Human Presence Acquired June 25, 2011, and June 22, 2010, these
false-color images compare conditions along the Souris River, which reached a historic crest
at Minot, North Dakota in June 2011. Land Floods Acquired May 11, 2011, and April 21, 2007,
these false-color images show the Mississippi River near Natchez, Mississippi. The image from

May 2011 shows flooded conditions. Land Floods September 6, 2020JPEGSeptember 7, 2023JPEGSeptember
6, 2020September 7, 2023September 6, 2020JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter
rapidly growing in volume just a few years earlier, northwest Iran’s Lake Urmia nearly dried
out in autumn 2023. The largest lake in the Middle East and one of the largest hypersaline
lakes on Earth at its greatest extent, Lake Urmia has for the most part transformed into a

vast, dry salt flat. On September 7, 2023, the OLI-2 (Operational Land Imager-2) on Landsat
9 captured this image (right) of the desiccated lakebed. It stands in contrast to the image
from three years earlier (left), acquired by the OLI on Landsat 8 on September 8, 2020, when
water filled most of the basin and salt deposits were only visible around the perimeter of
the lake. The replenishment followed a period of above-average precipitation that sent a surge

of freshwater into the basin, expanding its watery footprint. Drier conditions have since
brought levels back down. The longer-term trend for Urmia has been one toward drying. In 1995,
Lake Urmia reached a high-water mark; then in the ensuing two decades, the lake level dropped
more than 7 meters (23 feet) and lost approximately 90 percent of its area. Consecutive droughts,
agricultural water use, and dam construction on rivers feeding the lake have contributed to

the decline. A shrinking Lake Urmia has implications for ecological and human health. The
lake, its islands, and surrounding wetlands comprise valuable habitat and are recognized as
a UNESCO Biosphere Reserve, Ramsar site, and national park. The area provides breeding grounds
for waterbirds such as flamingos, white pelicans, and white-headed ducks, as well as a stopover
for migratory species. However, with low lake levels, what water remains becomes more saline

and taxes the populations of brine shrimp and other food sources for larger animals. A shrinking
lake also increases the likelihood of dust from the exposed lakebed becoming swept up by winds
and degrading air quality. Recent studies have linked the low water levels in Lake Urmia with
respiratory health impacts among the local population.The relative effects of climate, water
usage, and dams on Lake Urmia’s water level is a topic of debate. The lake did see some recovery

during a 10-year restoration program beginning in 2013. However, the efficacy of that effort
has been difficult to parse since strong rains also fell during that period. Some research
has concluded that climatic factors were primarily responsible for the recovery. NASA Earth
Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey.
Story by Lindsey Doermann.View this area in EO ExplorerA few years after a fresh influx of

water raised its levels, the large lake has nearly gone dry.Image of the Day for October 10,
2023 Image of the Day Land Water View more Images of the Day:Water levels are at their lowest
since 1937. Image of the Day Water Drought Fires Long and short. Deep and shallow. Salty and
fresh. Blue and brown. These are Africa’s Lake Tanganyika and Lake Rukwa. Image of the Day
Land Water In May 2016, the reservoir behind Hoover Dam reached its lowest level since the

1930s. Image of the Day Water When the water gets saltier in Iran’s largest lake, the microscopic
inhabitants can turn the water dark red. Image of the Day Water Water Color July 1 - September
30, 2023MPEG For several months in 2023, global sea surface temperatures reached record-high
levels, fueled by decades of human-caused climate warming and a recent boost from the natural
climate phenomenon El Niño. Some areas—including the seas around Florida, Cuba, and the Bahamas—saw

particularly high temperatures, with implications for the health of coral reefs.Corals thrive
within a small range of temperatures and become stressed when water is too hot or cold. Bleaching
occurs when stressed corals expel the algae that live inside them, stripping corals of their
color. Extreme bleaching can leave a reef susceptible to starvation, disease, and even death.
Observations made by divers in the Florida Keys found that the marine heatwave in summer 2023

caused widespread bleaching.Stress on corals can also be detected using data from satellites.
This animation shows the evolution of accumulated heat stress from July through September
2023. The colors depict “degree heating weeks” (°C-weeks)—a measure that provides an estimate
of the severity and duration of thermal stress. Data for the product are compiled by NOAA’s
Coral Reef Watch, which blends observations from polar orbiting satellites such as the NASA-NOAA

Suomi NPP, and from geostationary satellites such as GOES, with computer models.Observations
have shown that when the accumulated heat stress reaches a value of 4, significant coral bleaching
can result. At values of 8, coral bleaching and widespread mortality are likely. By midway
through this animation, in August, heat stress across much of the region already soared well
above both of those thresholds. According to NOAA, cumulative heat stress by late September

2023 hit 22°C-weeks (40°F-weeks), nearly triple the previous record for the region.Bleaching
was already observed in some areas as early as July. Notice that areas of coral reef (gray)
near the Florida Keys, Cuba, and the Bahamas, are among the first areas to show high cumulative
heat stress. Hurricane Idalia in late August helped cool surface waters somewhat, but only
temporarily.Nearing mid-October, waters around the Florida Keys were under a bleaching watch.

Further south, waters around parts of Cuba and the Bahamas remained at bleaching alert level
2, the highest level of the scale, signifying that severe bleaching and mortality are likely.NASA
Earth Observatory animation by Wanmei Liang, using Daily 5km Degree Heating Weeks data from
Coral Reef Watch. Coral reef data from UNEP-WCMC, WorldFish Centre, WRI, TNC. Story by Kathryn
Hansen.View this area in EO ExplorerThe seas around Florida, Cuba, and the Bahamas saw large

accumulations of heat stress beginning in summer 2023, with implications for the health of
coral reefs.Image of the Day for October 16, 2023 Image of the Day Water Temperature Extremes
View more Images of the Day:Warmer-than-average temperatures are showing up locally and globally,
with consequences for people, landscapes, and ecosystems. Image of the Day Water Image of
the Day Life Water Image of the Day Heat Life Water Studying corals from above could help

scientists understand how these critical ecosystems will weather a changing climate. Image
of the Day Land Life Water January 22 - July 26, 2023JPEGOne of the wettest wet seasons in
northern Australia transformed large areas of the country’s desert landscape over the course
of many months in 2023. A string of major rainfall events that dropped 690 millimeters (27
inches) between October 2022 and April 2023 made it the sixth-wettest season on record since

1900–1901.This series of false-color images illustrates the rainfall’s months-long effects
downstream in the Lake Eyre Basin. Water appears in shades of blue, vegetation is green, and
bare land is brown. The images were acquired by the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite between January and July 2023.In the January 22 image (left),
water was coursing through seasonally dry channels of the Georgina River and Eyre Creek following

weeks of heavy rains in northern Queensland. By April 21 (middle), floodwaters had reached
further downstream after another intense period of precipitation in March. This scene shows
that water had filled in some of the north-northwest trending ridges that are part of a vast
fossil landscape of wind-formed dunes, while vegetation had emerged in wet soil upstream.
Then by July 26 (right), the riverbed had filled with even more vegetation.The Georgina River

and Eyre Creek drain approximately 210,000 square kilometers (81,000 square miles), nearly
the area of the United Kingdom. Visible in the lower part of the images, the lake gets refreshed
about every three years; when it reaches especially high levels, it may take 18 months to
2 years to dry up. Two smaller neighboring lakes flood seasonally. These three lakes and surrounding
floodplains support hundreds of thousands of waterbirds and are designated as an Important

Bird Area.Seasonal flooding is a regular occurrence in these desert river systems. However,
the events of the 2022-2023 rainy season stood out in several ways. They occurred while La
Niña conditions were in place over the tropical Pacific Ocean. (The wettest seasons in northern
Australia have all occurred during La Niña years, according to Australia’s Bureau of Meteorology.)
In addition, major rains occurring in succession, as was the case with the January and March

events, have the overall effect of prolonging floods. That’s because vegetation that grows
after the first event slows down the pulse of water that comes through in the next rain event.The
high water has affected both local communities and ecosystems. Floods have inundated cattle
farms and isolated towns on temporary islands. At the same time, they are a natural feature
of the “boom-and-bust” ecology of Channel Country, providing habitat and nutrients that support

biodiversity.NASA Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS
LANCE and GIBS/Worldview. Story by Lindsey Doermann.View this area in EO ExplorerRepeated
heavy rains in Australia set off waves of new growth across Channel Country.Image of the Day
for August 7, 2023 Image of the Day Land Water View more Images of the Day: Floods The waves
off the coast of Teahupo’o can heave a crushing amount of water toward the shore and onto

unlucky surfers. Image of the Day Water Waves of heavy rainfall left towns and farmland under
water in October 2022. Image of the Day Water Floods Acquired February 26, 2011, and February
5, 2011, these false-color images show the impact of heavy rains in marshy areas southeast
of Georgetown, Guyana. Land Floods August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September
18, 2023August 25, 2023JPEGSeptember 18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone

in the Mediterranean inundated cities along the northeastern coast of Libya in early September
2023, causing thousands of deaths. The port city of Derna (Darnah), home to about 90,000 people,
was one of the worst hit by the storm and suffered extensive flooding and damage. On September
10 and 11, over 100 millimeters (4 inches) of rain fell on Derna. The city lies at the end
of a long, narrow valley, called a wadi, which is dry except during the rainy season. Floods

triggered two dams along the wadi to collapse. The failure of the second dam, located just
one kilometer inland of Derna, unleashed 3- to 7-meter-high floodwater that tore through the
city. According to news reports, the flash floods destroyed roads and swept entire neighborhoods
out to sea. The images above show the city before and after the storm. The image on the right,
acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded

banks of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears
muddier than in the image on the left, which shows the same area on August 25 and was acquired
by Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate
that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the

storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest
in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023
Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers

out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm
dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours

in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational

to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the
U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color

data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with
darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in

the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s
surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.

However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the
remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered

in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had
been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability

in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,
the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from

materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming
climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean

color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)
satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the

diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image
of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level

measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe
Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage

of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities
issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires

have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks
disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced

in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely
a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton

growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite
sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.

Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility
was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution

of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary
Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran

Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,
making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa

(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and
hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts

allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported

by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach

to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during

this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast

are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere
Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust

and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay
18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling

in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters
(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2
(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other

image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.
Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University
of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use

in the nearby community of Paine, increasing water use by farmers and in homes and pools,
as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,
according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the

water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how
long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome
interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much

longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from
the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start
pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly

22 years, but groundwater levels still suffer from years of drought. Image of the Day Land
Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists
could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over

water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for
their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late
1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over

the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and
operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember
10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer

and early fall of 2023. In September, low water levels limited barge shipments downriver and
threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the
Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This

is the second year in a row drought has caused the river to fall to near-record lows at many
gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That
was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they

are measured with respect to a chosen reference point. That is why some gauge height measurements
are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally
decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in

2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.
In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department
of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts

drought intensity in progressive shades of orange to red. It is based on an analysis of climate,
soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring
effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in

states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of
soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions
along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river

was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported
down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the
Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines

Parish are under drinking water advisories and have relied on bottled water for cooking and
drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast
Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren

Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States
Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the
river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect

water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily
passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests
in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low

water levels are making it difficult to ship goods down the river and allowing a wedge of
saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced
algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long

lake has a watershed that spans one million square kilometers (386,000 square miles), draining
some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September
25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated

that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of
the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients
like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm

the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that
can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents
and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer

months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels
were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between
1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous

to the lake were increased agricultural activities in the watershed and a higher frequency
of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019
study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a

measure of phytoplankton biomass, were on average more than twice as high in the south basin,
compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx
of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View

more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are
sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface
of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the

Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount
St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water
Human Presence Remote Sensing October 8, 2022JPEGOctober 3, 2023JPEGOctober 8, 2022October
3, 2023October 8, 2022JPEGOctober 3, 2023JPEGOctober 3, 2023JPEGJuly through October fall

within the dry season in the western and northern Amazon rainforest, but a particularly acute
lack of rain during this period in 2023 has pushed the region into a severe drought.The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image (right) of the parched
Rio Negro in the Brazilian province of Amazonas near the city of Manaus on October 3, 2023.
On that date, the level of the river, the largest tributary of the Amazon River, had dropped

to 15.14 meters (50.52 feet), according to data collected by the Port of Manaus. For comparison,
the image on the left shows the same area on October 8, 2022, when the water level was 19.59
meters, a more typical level for October. Rio Negro water levels continued to drop in the
days after the image was collected, reaching a record low of 13.49 meters on October 17, 2023.Some
areas in the Amazon River’s watershed have received less rain between July and September than

any year since 1980, Reuters reported. The drought has been particularly severe in the Rio
Negro watershed in northern Amazonas, as well as parts of southern Venezuela and southern
Colombia.“Overall, this is a pretty unusual and extreme situation,” said René Garreaud, an
atmospheric scientist at the University of Chile. “The primary culprit exacerbating the drought
appears to be El Niño.” This cyclical warming of surface waters in the central-eastern Pacific

functions somewhat like a boulder in the middle of a stream, disrupting atmospheric circulation
patterns in ways that lead to wetter conditions over the equatorial Pacific and drier conditions
over the Amazon Basin.According to news outlets, the low river water levels on the Rio Negro
and other nearby rivers have disrupted drinking water supplies in hundreds of communities,
slowed commercial navigation, and led to fish and dolphin die-offs.Manaus, the capital and

largest city of the Brazilian state of Amazonas, is the primary transportation hub for the
upper Amazon, serving as an important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include chemical, ship, and electrical
equipment manufacturing.NASA Earth Observatory images by Wanmei Liang, using Landsat data
from the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe water

level of the largest tributary of the Amazon River has hit a record low.Image of the Day for
October 18, 2023 Image of the Day Water Human Presence View more Images of the Day:The impact
of severe drought on the Negro River, a tributary of the Amazon River, and other rivers in
the basin is dramatically evident in this pair of images, which show that every body of water
has shrunk in 2010 compared to 2008. Image of the Day Atmosphere Land The volume of water

in New Mexico’s largest reservoir has dropped to historic lows due to drought and persistent
demand. Image of the Day Water Human Presence Acquired June 25, 2011, and June 22, 2010, these
false-color images compare conditions along the Souris River, which reached a historic crest
at Minot, North Dakota in June 2011. Land Floods Acquired May 11, 2011, and April 21, 2007,
these false-color images show the Mississippi River near Natchez, Mississippi. The image from

May 2011 shows flooded conditions. Land Floods September 6, 2020JPEGSeptember 7, 2023JPEGSeptember
6, 2020September 7, 2023September 6, 2020JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter
rapidly growing in volume just a few years earlier, northwest Iran’s Lake Urmia nearly dried
out in autumn 2023. The largest lake in the Middle East and one of the largest hypersaline
lakes on Earth at its greatest extent, Lake Urmia has for the most part transformed into a

vast, dry salt flat. On September 7, 2023, the OLI-2 (Operational Land Imager-2) on Landsat
9 captured this image (right) of the desiccated lakebed. It stands in contrast to the image
from three years earlier (left), acquired by the OLI on Landsat 8 on September 8, 2020, when
water filled most of the basin and salt deposits were only visible around the perimeter of
the lake. The replenishment followed a period of above-average precipitation that sent a surge

of freshwater into the basin, expanding its watery footprint. Drier conditions have since
brought levels back down. The longer-term trend for Urmia has been one toward drying. In 1995,
Lake Urmia reached a high-water mark; then in the ensuing two decades, the lake level dropped
more than 7 meters (23 feet) and lost approximately 90 percent of its area. Consecutive droughts,
agricultural water use, and dam construction on rivers feeding the lake have contributed to

the decline. A shrinking Lake Urmia has implications for ecological and human health. The
lake, its islands, and surrounding wetlands comprise valuable habitat and are recognized as
a UNESCO Biosphere Reserve, Ramsar site, and national park. The area provides breeding grounds
for waterbirds such as flamingos, white pelicans, and white-headed ducks, as well as a stopover
for migratory species. However, with low lake levels, what water remains becomes more saline

and taxes the populations of brine shrimp and other food sources for larger animals. A shrinking
lake also increases the likelihood of dust from the exposed lakebed becoming swept up by winds
and degrading air quality. Recent studies have linked the low water levels in Lake Urmia with
respiratory health impacts among the local population.The relative effects of climate, water
usage, and dams on Lake Urmia’s water level is a topic of debate. The lake did see some recovery

during a 10-year restoration program beginning in 2013. However, the efficacy of that effort
has been difficult to parse since strong rains also fell during that period. Some research
has concluded that climatic factors were primarily responsible for the recovery. NASA Earth
Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey.
Story by Lindsey Doermann.View this area in EO ExplorerA few years after a fresh influx of

water raised its levels, the large lake has nearly gone dry.Image of the Day for October 10,
2023 Image of the Day Land Water View more Images of the Day:Water levels are at their lowest
since 1937. Image of the Day Water Drought Fires Long and short. Deep and shallow. Salty and
fresh. Blue and brown. These are Africa’s Lake Tanganyika and Lake Rukwa. Image of the Day
Land Water In May 2016, the reservoir behind Hoover Dam reached its lowest level since the

1930s. Image of the Day Water When the water gets saltier in Iran’s largest lake, the microscopic
inhabitants can turn the water dark red. Image of the Day Water Water Color July 1 - September
30, 2023MPEG For several months in 2023, global sea surface temperatures reached record-high
levels, fueled by decades of human-caused climate warming and a recent boost from the natural
climate phenomenon El Niño. Some areas—including the seas around Florida, Cuba, and the Bahamas—saw

particularly high temperatures, with implications for the health of coral reefs.Corals thrive
within a small range of temperatures and become stressed when water is too hot or cold. Bleaching
occurs when stressed corals expel the algae that live inside them, stripping corals of their
color. Extreme bleaching can leave a reef susceptible to starvation, disease, and even death.
Observations made by divers in the Florida Keys found that the marine heatwave in summer 2023

caused widespread bleaching.Stress on corals can also be detected using data from satellites.
This animation shows the evolution of accumulated heat stress from July through September
2023. The colors depict “degree heating weeks” (°C-weeks)—a measure that provides an estimate
of the severity and duration of thermal stress. Data for the product are compiled by NOAA’s
Coral Reef Watch, which blends observations from polar orbiting satellites such as the NASA-NOAA

Suomi NPP, and from geostationary satellites such as GOES, with computer models.Observations
have shown that when the accumulated heat stress reaches a value of 4, significant coral bleaching
can result. At values of 8, coral bleaching and widespread mortality are likely. By midway
through this animation, in August, heat stress across much of the region already soared well
above both of those thresholds. According to NOAA, cumulative heat stress by late September

2023 hit 22°C-weeks (40°F-weeks), nearly triple the previous record for the region.Bleaching
was already observed in some areas as early as July. Notice that areas of coral reef (gray)
near the Florida Keys, Cuba, and the Bahamas, are among the first areas to show high cumulative
heat stress. Hurricane Idalia in late August helped cool surface waters somewhat, but only
temporarily.Nearing mid-October, waters around the Florida Keys were under a bleaching watch.

Further south, waters around parts of Cuba and the Bahamas remained at bleaching alert level
2, the highest level of the scale, signifying that severe bleaching and mortality are likely.NASA
Earth Observatory animation by Wanmei Liang, using Daily 5km Degree Heating Weeks data from
Coral Reef Watch. Coral reef data from UNEP-WCMC, WorldFish Centre, WRI, TNC. Story by Kathryn
Hansen.View this area in EO ExplorerThe seas around Florida, Cuba, and the Bahamas saw large

accumulations of heat stress beginning in summer 2023, with implications for the health of
coral reefs.Image of the Day for October 16, 2023 Image of the Day Water Temperature Extremes
View more Images of the Day:Warmer-than-average temperatures are showing up locally and globally,
with consequences for people, landscapes, and ecosystems. Image of the Day Water Image of
the Day Life Water Image of the Day Heat Life Water Studying corals from above could help

scientists understand how these critical ecosystems will weather a changing climate. Image
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Scientific Data volume 7, Article number: 112 (2020) Cite this article 30k Accesses126 Citations88
AltmetricMetrics detailsRemotely sensed biomass carbon density maps are widely used for myriad
scientific and policy applications, but all remain limited in scope. They often only represent
a single vegetation type and rarely account for carbon stocks in belowground biomass. To date,
no global product integrates these disparate estimates into an all-encompassing map at a scale

appropriate for many modelling or decision-making applications. We developed an approach for
harmonizing vegetation-specific maps of both above and belowground biomass into a single,
comprehensive representation of each. We overlaid input maps and allocated their estimates
in proportion to the relative spatial extent of each vegetation type using ancillary maps
of percent tree cover and landcover, and a rule-based decision schema. The resulting maps

consistently and seamlessly report biomass carbon density estimates across a wide range of
vegetation types in 2010 with quantified uncertainty. They do so for the globe at an unprecedented
300-meter spatial resolution and can be used to more holistically account for diverse vegetation
carbon stocks in global analyses and greenhouse gas inventories.Measurement(s)biomass carbon
densityTechnology Type(s)digital curationFactor Type(s)climatic zone • above or below ground

• land coverSample Characteristic - Environmentorganic materialSample Characteristic - LocationEarth
(planet)Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.11872383Terrestrial
ecosystems store vast quantities of carbon (C) in aboveground and belowground biomass1. At
any point in time, these stocks represent a dynamic balance between the C gains of growth
and C losses from death, decay and combustion. Maps of biomass are routinely used for benchmarking

biophysical models2,3,4, estimating C cycle effects of disturbance5,6,7, and assessing biogeographical
patterns and ecosystem services8,9,10,11. They are also critical for assessing climate change
drivers, impacts, and solutions, and factor prominently in policies like Reducing Emissions
from Deforestation and Forest Degradation (REDD+) and C offset schemes12,13,14. Numerous methods
have been used to map biomass C stocks but their derivatives often remain limited in either

scope or extent12,15. There thus remains a critical need for a globally harmonized, integrative
map that comprehensively reports biomass C across a wide range of vegetation types.Most existing
maps of aboveground biomass (AGB) and the carbon it contains (AGBC) are produced from statistical
or data-driven methods relating field-measured or field-estimated biomass densities and spaceborne
optical and/or radar imagery12,15,16. They largely focus on the AGB of trees, particularly

those in tropical landscapes where forests store the majority of the region’s biotic C in
aboveground plant matter. Land cover maps are often used to isolate forests from other landcover
types where the predictive model may not be appropriate such that forest AGB maps intentionally
omit AGB stocks in non-forest vegetation like shrublands, grasslands, and croplands, as well
as the AGB of trees located within the mapped extent of these excluded landcovers17. Non-forest

AGB has also been mapped to some extent using similar approaches but these maps are also routinely
masked to the geographic extent of their focal landcover18,19,20,21. To date, there has been
no rigorous attempt to harmonize and integrate these landcover-specific, remotely sensed products
into a single comprehensive and temporally consistent map of C in all living biomass.Maps
of belowground biomass (BGB) and carbon density (BGBC) are far less common than those of AGB

because BGB cannot be readily observed from space or airborne sensors. Consequently, BGB is
often inferred from taxa-, region-, and/or climate-specific “root-to-shoot” ratios that relate
the quantity of BGB to that of AGB22,23,24. These ratios can be used to map BGB by spatially
applying them to AGB estimates using maps of their respective strata5. In recent years, more
sophisticated regression-based methods have been developed to predict root-to-shoot ratios

of some landcover types based on covariance with other biophysical and/or ecological factors25,26.
When applied spatially, these methods can allow for more continuous estimates of local BGB5,27.
Like AGBC, though, few attempts have been made to comprehensively map BGBC for the globe.Despite
the myriad of emerging mapping methods and products, to date, the Intergovernmental Panel
on Climate Change (IPCC) Tier-1 maps by Ruesch and Gibbs28 remains the primary source of global

AGBC and BGBC estimates that transcend individual landcover types. These maps, which represents
the year 2000, were produced prior to the relatively recent explosion of satellite-based AGB
maps and they therefore rely on an alternative mapping technique called “stratify and multiply”15,
which assigns landcover-specific biomass estimates or “defaults” (often derived from field
measurements or literature reviews) to the corresponding classified grid cells of a chosen

landcover map12. While this approach yields a comprehensive wall-to-wall product, it can fail
to capture finer-scale spatial patterns often evident in the field and in many satellite-based
products12,15. The accuracy of these maps is also tightly coupled to the quality and availability
of field measurements29 and the thematic accuracy and discontinuity of the chosen landcover
map.Given the wealth of landcover-specific satellite based AGB maps, a new harmonization method

akin to “stratify and multiply” is needed to merge the validated spatial detail of landcover-specific
remotely sensed biomass maps into a single, globally harmonized product. We developed such
an approach by which we (i) overlay distinct satellite-based biomass maps and (ii) proportionately
allocate their estimates to each grid cell (“overlay and allocate”). Specifically, we overlay
continental-to-global scale remotely sensed maps of landcover-specific biomass C density and

then allocate fractional contributions of each to a given grid cell using additional maps
of percent tree cover, thematic landcover and a rule-based decision tree. We implement the
new approach here using temporally consistent maps of AGBC as well as matching derived maps
of BGBC to generate separate harmonized maps of AGBC and BGBC densities. In addition, we generate
associated uncertainty layers by propagating the prediction error of each input dataset. The

resulting global maps consistently represent biomass C and associated uncertainty across a
broad range of vegetation in the year 2010 at an unprecedented 300 meter (m) spatial resolution.Our
harmonization approach (Fig. 1) relies on independent, landcover-specific biomass maps and
ancillary layers, which we compiled from the published literature (Table 1). When published
maps did not represent our epoch of interest (i.e. grasslands and croplands) or did not completely

cover the necessary spatial extent (i.e. tundra vegetation), we used the predictive model
reported with the respective map to generate an updated version that met our spatial and temporal
requirements. We then used landcover specific root-to-shoot relationships to generate matching
BGBC maps for each of the input AGBC maps before implementing the harmonization procedure.
Below we describe, in detail, the methodologies used for mapping AGBC and BGBC of each landcover

type and the procedure used to integrate them.Generalized, three-step workflow used to create
harmonized global biomass maps. In step one, woody AGB maps are prepared, combined, converted
to AGBC density and used to create separate but complementary maps of BGBC. In step two, a
similar workflow is used to generate matching maps of AGBC and BGBC for tundra vegetation,
grasses, and annual crops. In step three, all maps are combined using a rule-based decision

tree detailed in Fig. 3 to generate comprehensive, harmonized global maps. All input data
sources are listed and described in Table 1.Since the first remotely sensed woody AGB maps
were published in the early 1990s, the number of available products has grown at an extraordinary
pace16 and it can thus be challenging to determine which product is best suited for a given
application. For our purposes, we relied on the GlobBiomass AGB density map30 as our primary

source of woody AGB estimates due to its precision, timestamp, spatial resolution, and error
quantification. It was produced using a combination of spaceborne optical and synthetic aperture
radar (SAR) imagery and represents the year 2010 at a 100 m spatial resolution – making it
the most contemporary global woody AGB currently available and the only such map available
for that year. Moreover, GlobBiomass aims to minimize prediction uncertainty to less than

30% and a recent study suggests that it has high fidelity for fine-scale applications31.The
GlobBiomass product was produced by first mapping the growing stock volume (GSV; i.e. stem
volume) of living trees, defined following Food and Agriculture Organization (FAO) guidelines32
as those having a diameter at breast height (DBH) greater than 10 centimeters (cm). AGB density
was then determined from GSV by applying spatialized biomass expansion factors (BEFs) and

wood density estimates. These factors were mapped using machine learning methods trained from
a suite of plant morphological databases that compile thousands of field measurements from
around the globe33. The resulting AGB estimates represent biomass in the living structures
(stems, branches, bark, twigs) of trees with a DBH greater than 10 cm. This definition may
thereby overlook AGB of smaller trees and/or shrubs common to many global regions. Unlike

other maps, though, the GlobBiomass product employs a subpixel masking procedure that retains
AGB estimates in 100 m grid cells in which any amount of tree cover was detected in finer
resolution (30 m) imagery34. This unique procedure retains AGB estimates in tree-sparse regions
like savannahs, grasslands, croplands, and agroforestry systems where AGB is often overlooked17,
as well as in forest plantations. The GlobBiomass product is the only global map that also

includes a dedicated uncertainty layer reporting the standard error of prediction. We used
this layer to propagate uncertainty when converting AGB to AGBC density, modelling BGBC, and
integrating with C density estimates of other vegetation types.Bouvet et al.35 – some of whom
were also participants of the GlobBiomass project – independently produced a separate AGB
density map for African savannahs, shrublands and dry woodlands circa 2010 at 25 m spatial

resolution35 (hereafter “Bouvet map”), which we included in our harmonized product to begin
to address the GlobBiomass map’s potential omission of small trees and shrubs that do not
meet the FAO definition of woody AGB. This continental map of Africa is based on a predictive
model that directly relates spaceborne L-band SAR imagery – an indirect measure of vegetation
structure that is sensitive to low biomass densities36 – with region-specific, field-measured

AGB. Field measurements (n = 144 sites) were compiled from 7 different sampling campaigns
– each specifically seeking training data for biomass remote sensing – that encompassed 8
different countries35. The resulting map is not constrained by the FAO tree definition and
is masked to exclude grid cells in which predicted AGB exceeds 85 megagrams dry mater per
hectare (Mg ha−1) – the threshold at which the SAR-biomass relationship saturates. To avoid

extraneous prediction, it further excludes areas identified as “broadleaved evergreen closed-to-open
forest”, “flooded forests”, “urban areas” and “water bodies” by the European Space Agency’s
Climate Change Initiative (CCI) Landcover 2010 map37 and as “bare areas” in the Global Land
Cover (GLC) 2000 map38. While the Bouvet map is not natively accompanied by an uncertainty
layer, its authors provided us with an analytic expression of its uncertainty (SE; standard

error of prediction) as a function of estimated AGB (Eq. 1) which we used to generate an uncertainty
layer for subsequent error propagation.We combined the GlobBiomass and Bouvet products to
generate a single woody biomass map by first upscaling each map separately to a matching 300
m spatial resolution using an area-weighted average to aggregate grid cells, and then assigning
the Bouvet estimate to all overlapping grid cells, except those identified by the CCI Landcover

2010 map as closed or flooded forest types (Online-only Table 1) which were not within the
dryland domain of the Bouvet map. While more complex harmonization procedures based on various
averaging techniques have been used by others39,40, their fidelity remains unclear since they
fail to explicitly identify and reconcile the underlying source of the inputs’ discrepancies41.
We thus opted to use a more transparent ruled-based approach when combining these two woody

biomass maps, which allows users to easily identify the source of a grid cell’s woody biomass
estimate. Given the local specificity of the training data used to produce the Bouvet map,
we chose to prioritize its predictions over those of the GlobBiomass product when within its
domain. In areas of overlap, the Bouvet map values tend to be lower in moist regions and higher
in dryer regions (Fig. 2), though, where used, these differences rarely exceed ±25 megagrams

C per hectare (MgC ha−1).Difference between underlying woody aboveground biomass maps in Africa.
Maps considered are the GlobBiomass30 global map and the Bouvet35 map of Africa. Both maps
were aggregated to a 300 m spatial resolution and converted to C density prior to comparison
using the same schema. The difference map was subsequently aggregated to a 3 km spatial resolution
and reprojected for visualization. Negative values denote lower estimates by Bouvet et al.35,

while positive values denote higher estimates.We then converted all woody AGB estimates to
AGBC by mapping climate and phylogeny-specific biomass C concentrations from Martin et al.42.
Climate zones were delineated by aggregating classes of the Köppen-Gieger classification43
(Table 2) to match those of Martin et al.42. Phylogenetic classes (angiosperm, gymnosperm
and mixed/ambiguous) were subsequently delineated within each of these zones using aggregated

classes of the CCI Landcover 2010 map (Online-only Table 1). Martin et al.42 only report values
for angiosperms and gymnosperms so grid cells with a mixed or ambiguous phylogeny were assigned
the average of the angiosperm and gymnosperm values and the standard error of this value was
calculated from their pooled variance. Due to residual classification error in the aggregated
phylogenetic classes, we weighted the phylogeny-specific C concentration within each climate

zone by the binary probability of correctly mapping that phylogeny (i.e. user’s accuracy)44
using Eq. 2where, within each climate zone, μc is the mean probability-weighted C concentration
of the most probable phylogeny, μm is the mean C concentration of that phylogeny from Martin
et al.42, pm is the user’s accuracy of that phylogeny’s classification (Table 3), and μn and
μo are the mean C concentrations of the remain phylogenetic classes from Martin et al.42.

Standard error estimates for these C concentrations were similarly weighted using summation
in quadrature (Eq. 3)where \({\sigma }_{c}\) is the probability-weighted standard error of
the most probable phylogeny’s C concentration and \({\sigma }_{m}\), \({\sigma }_{n}\) and
\({\sigma }_{o}\) are the standard errors of the respective phylogeny-specific C concentrations
from Martin et al.42. Probability-weighted C concentrations used are reported in Table 4.Mapped,

probability-weighted C estimates were then arithmetically applied to AGB estimates. Uncertainty
associated with this correction was propagated using summation in quadrature of the general
form (Eq. 4)where \({\mu }_{f}=f(i,j,\ldots ,k)\), \({\sigma }_{f}\) is the uncertainty of
μf, and \({\sigma }_{i},{\sigma }_{j},\ldots ,{\sigma }_{k}\), are the respective uncertainty
estimates of the dependent parameters (standard error unless otherwise noted). Here, μf, is

the estimated AGBC of a given grid cell, and is the product of its woody AGB estimate, and
its corresponding C concentration.The tundra and portions of the boreal biome are characterized
by sparse trees and dwarf woody shrubs as well as herbaceous cover that are not included in
the GlobBiomass definition of biomass. AGB density of these classes has been collectively
mapped by Berner et al.18,45 for the North Slope of Alaska from annual Landsat imagery composites

of the normalized difference vegetation index (NDVI) and a non-linear regression-based model
trained from field measurements of peak AGB that were collected from the published literature
(n = 28 sites). Berner et al.18 note that while these field measurements did not constitute
a random or systematic sample, they did encompass a broad range of tundra plant communities.
In the absence of a global map and due the sparsity of high quality Landsat imagery at high

latitudes, we extended this model to the pan-Arctic and circumboreal regions using NDVI composites
created from daily 250 m MODIS Aqua and Terra surface reflectance images46,47 that were cloud
masked and numerically calibrated to Landsat ETM reflectance – upon which the tundra model
is based – using globally derived conversion coefficients48. We generated six separate 80th
percentile NDVI composites circa 2010 – one for each of the MODIS missions (Aqua and Terra)

in 2009, 2010 and 2011 – following Berner et al.18. We chose to use three years of imagery
(circa 2010) rather than just one (2010) to account for the potential influence that cloud
masking may exert upon estimates of the 80th NDVI percentile in a single year. We then applied
the tundra AGB model to each composite, converted AGB estimates to AGBC by assuming a biomass
C fraction of 49.2% (SE = 0.8%)42 and generated error layers for each composite from the reported

errors of the AGB regression coefficients and the biomass C conversion factor using summation
in quadrature as generally described above (Eq. 4). A single composite of tundra AGBC circa
2010 was then created as the pixelwise mean of all six composites. We also generated a complementary
uncertainty layer representing the cumulative standard error of prediction, calculated as
the pixelwise root mean of the squared error images in accordance with summation in quadrature.

Both maps were upscaled from their native 250 m spatial resolution to a 300 m spatial resolution
using an area weighted aggregation procedure, whereby pixels of the 300 m biomass layer was
calculated as the area weighted average of contained 250 m grid cells, and the uncertainty
layer was calculated – using summation in quadrature – as the root area-weighted average of
the contained grid cells squared.Grassland AGBC density was modelled directly from maximum

annual NDVI composites using a non-linear regression-based model developed by Xia et al.19
for mapping at the global scale. This model was trained by relating maximum annual NDVI as
measured by the spaceborne Advanced Very High-Resolution Radiometer (AVHRR) sensor to globally
distributed field measurements of grassland AGBC that were compiled from the published literature
(81 sites for a total of 158 site-years). Like the tundra biomass training data, these samples

did not constitute a random or systematic sample but do encompass a comprehensive range of
global grassland communities. Given the inevitable co-occurrence of trees in the AVHRR sensor’s
8 km resolution pixels upon which the model is trained, it’s predictions of grassland AGBC
are relatively insensitive to the effects of co-occurring tree cover. We thereby assume that
its predictions for grid cells containing partial tree cover represent the expected herbaceous

AGBC density in the absence of those trees. Maximum model predicted AGBC (NDVI = 1) is 2.3
MgC ha−1 which is comparable to the upper quartile of herbaceous AGBC estimates from global
grasslands49 and suggests that our assumption will not lead to an exaggerated estimation.
For partially wooded grid cells, we used modelled grassland AGBC density to represent that
associated with the herbaceous fraction of the grid cell in a manner similar to Zomer et al.17

as described below (See “Harmonizing Biomass Carbon Maps”).We applied the grassland AGBC model
to all grid cells of maximum annual NDVI composites produced from finer resolution 16-day
(250 m) MODIS NDVI imagery composites circa 201050,51. Here again, three years of imagery
were used to account for potential idiosyncrasies in a single year’s NDVI composites resulting
from annual data availability and quality. As with AGB of tundra vegetation, annual composites

(2009–2011) were constructed separately from cloud-masked imagery collected by both MODIS
missions (Aqua and Terra; n = 6) and then numerically calibrated to AVHRR reflectance using
globally derived conversion coefficients specific to areas of herbaceous cover52. We then
applied the AGBC model to each of these composites and estimated error for each composite
from both the AVHRR calibration (standard deviation approximated from the 95% confidence interval

of the calibration scalar) and the AGBC model (relative RMSE) using summation in quadrature.
A single map of grassland AGBC circa 2010 was then created as the pixelwise mean of all six
composites and an associated error layer was created as the pixelwise root mean of the squared
error images. Both maps were aggregated from their original 250 m resolution to 300 m to facilitate
harmonization using the area-weighted procedure described previously for woody and tundra

vegetation (see section 1.2).Prior to harvest, cropland biomass can also represent a sizable
terrestrial C stock. In annually harvested cropping systems, the maximum standing biomass
of these crops can be inferred from annual net primary productivity (ANPP). While spaceborne
ANPP products exist, they generally perform poorly in croplands53,54. Instead, cropland ANPP
is more commonly derived from crop yields20,21,53. We used globally gridded, crop-specific

yields of 70 annually harvested herbaceous commodity crops circa 2000 by Monfreda et al.20
– the only year in which these data were available. These maps were produced by spatially
disaggregating crop-yield statistics for thousands of globally distributed administrative
units throughout the full extent of a satellite-based cropland map20. These maps were combined
with crop-specific parameters (Online-only Table 2) to globally map AGBC as aboveground ANPP

for each crop following the method of Wolf et al.21. This method can be simplified as (Eq.
5)where y is the crop’s yield (Mg ha−1), ω is the dry matter fraction of its harvested biomass,
h is its harvest index (fraction of total AGB collected at harvest) and c is the carbon content
fraction of its harvested dry mass. This simplification assumes, following Wolf et al.21,
that 2.5% of all harvested biomass is lost between the field and farmgate and that unharvested

residue and root mass is 44% C.Total cropland AGBC density was then calculated as the harvested-area-weighted
average of all crop-specific AGBC estimates within a given grid cell. Since multiple harvests
in a single year can confound inference of maximum AGBC from ANPP, we further determined the
harvest frequency (f) of each grid cell by dividing a cell’s total harvested area (sum of
the harvested area of each crop reported within a given grid cell) by its absolute cropland

extent as reported in a complementary map by Ramankutty et al.55. If f was greater than one,
multiple harvests were assumed to have occurred and AGBC was divided by f to ensure that AGBC
estimates did not exceed the maximum standing biomass density.Since the yields of many crops
and, by association, their biomass have changed considerably since 200056,57, we calibrated
our circa 2000 AGBC estimates to the year 2010 using local rates of annual ANPP change (MgC

ha−1 yr−1) derived as the Theil-Sen slope estimator – a non-parametric estimator that is relatively
insensitive to outliers – of the full MODIS Terra ANPP timeseries (2000–2015)58. Total ANPP
change between 2000 and 2010 for each grid cell was calculated as ten times this annual rate
of change. Since MODIS ANPP represents C gains in both AGB and BGB, we proportionately allocated
aboveground ANPP to AGBC using the total root-to-shoot ratio derived from the circa 2000 total

crop AGBC and BGBC maps (described below). Since error estimates were not available for the
yield maps or the crop-specific parameters used to generate the circa 2000 AGBC map, estimated
error of the circa 2010 crop AGBC map was exclusively based on that of the 2000–2010 correction.
The error of this correction was calculated as the pixel-wise standard deviation of bootstrapped
simulations (n = 1000) in which a random subset of years was omitted from the slope estimator

in each iteration. The 8 km resolution circa 2000 AGBC map and error layer were resampled
to 1 km to match the resolution of MODIS ANPP using the bilinear method prior to ANPP correction
and then further resampled to 300 m to facilitate harmonization.Woody crops like fruit, nut,
and palm oil plantations were not captured using the procedure just described and their biomass
was instead assumed to be captured by the previously described woody biomass products which

retained biomass estimates in all pixels where any amount of tree cover was detected at the
sub-pixel level (see section 1.1).Matching maps of BGBC and associated uncertainty were subsequently
produced for each of the landcover-specific AGBC maps using published empirical relationships.With
the exception of savannah and shrubland areas, woody BGBC was modelled from AGBC using a multiple
regression model by Reich et al.25 that considers the phylogeny, mean annual temperature (MAT),

and regenerative origin of each wooded grid cell and that was applied spatially using maps
of each covariate in a fashion similar to other studies5,27. Tree phylogeny (angiosperm or
gymnosperm) was determined from aggregated classes of the CCI Landcover 2010 map37 (Online-only
Table 1) with phylogenetically mixed or ambiguous classes assumed to be composed of 50% of
each. MAT was taken from version 2 of the WorldClim bioclimatic variables dataset (1970–2000)

at 1 km resolution59 and resampled to 300 m using the bilinear method. Since there is not
a single global data product mapping forest management, we determined tree origin – whether
naturally propagated or planted – by combining multiple data sources. These data included
(i) a global map of “Intact Forest Landscapes” (IFL) in the year 201360 (a conservative proxy
of primary, naturally regenerating forests defined as large contiguous areas with minimal

human impact), (ii) a Spatial Database of Planted Trees (SDPT) with partial global coverage61,
(iii) national statistics reported by the FAO Global Forest Resources Assessment (FRA) on
the extent of both naturally regenerating and planted forests and woodlands within each country
in the year 201062, and (iv) national statistics reported by the FAOSTAT database (http://www.fao.org/faostat)
on the planted area of plantation crops in 2010. Within each country, we assumed that the

total area of natural and planted trees was equal to the corresponding FRA estimates. If the
FAOSTAT-reported area of tree crops exceeded FRA-reported planted area, the difference was
added to FRA planted total. All areas mapped as IFL were assumed to be of natural origin and
BGB was modelled as such. Likewise, besides the exceptions noted below, all tree plantations
mapped by the SDPT were assumed to be of planted origin. In countries where the extent of

the IFL or SDPT maps fell short of the FRA/FAOSTAT reported areas of natural or planted forests,
respectively, we estimated BGBC in the remaining, unknown-origin forest grid cells of that
country (BGBCu), as the probability-weighted average of the planted and natural origin estimates
using Eq. 6where \(BGB{C}_{p}\) and \(BGB{C}_{n}\) are the respective BGBC estimates for a
grid cell assuming entirely planted and natural origin, respectively, and \({\Delta }_{p}\)

and \({\Delta }_{n}\) are the respective differences between (i) the FRA/FAOSTAT and (ii)
mapped extent of planted and natural forest within the given grid cell’s country. While the
mapped extent of IFL forests within a given country never exceeded that country’s FRA reported
natural forest extent, there were infrequent cases (n = 22 of 257) in which the mapped extent
of tree plantations exceeded the corresponding FRA/FAOSTAT estimate of planted forest area.

In these cases, we down-weighted the BGB estimates of SDPT forests in a similar fashion such
that the weight of their planted estimate (\({\omega }_{p}\)) was equal to the quotient of
(i) the FRA/FAOSTAT planted area and (ii) the SDPT extent within the country, and the weight
of the natural origin estimate applied to the SDPT extent (\({\omega }_{n}\)) was equal to
\(1-{\omega }_{p}\).A BGBC error layer was then produced using summation in quadrature from

the standard error estimates of the model coefficients, the AGBC error layer, the relative
RMSE of MAT (27%), and the derived global uncertainty of the phylogeny layer. Phylogeny error
was calculated as the Bernoulli standard deviation (δ) of the binary probability (p) of correct
classification (i.e. “area weighted user’s accuracy”44; Table 3) using Eq. 7.Since savannahs
and shrublands are underrepresented in the regression-based model25, their BGBC was instead

estimated using static root-to-shoot ratios reported by Mokany et al.22, which are somewhat
conservative in comparison to the IPCC Tier-1 defaults23,24 put favoured for consistency with
methods used for grasslands (see below). Error was subsequently mapped from that of the AGBC
estimates and the root-to-shoot ratios applied (Table 5).BGBC of tundra vegetation was mapped
from AGBC using a univariate regression model derived by Wang et al.26 that predicts root-to-shoot

ratio as a function of MAT. We applied the model using the WorldClim version 2 MAT map59 and
propagated error from the AGBC estimates, the relative RMSE of MAT and the standard error
of regression coefficients. Where tundra AGB exceeded 25 Mg ha−1 – the maximum field-measured
shrub biomass reported by Berner et al.18 – vegetation was considered to include trees and
the Reich et al.25 method described earlier for woody vegetation was used instead.In the absence

of a continuous predictor of grassland root-to-shoot ratios, we applied climate specific root-to-shoot
ratios from Mokany et al.22 to the corresponding climate regions of the Köppen-Gieger classification43
(Table 2). Here, again, these ratios vary slightly from the IPCC Tier-1 defaults23,24 but
were chosen for their greater sample size and specificity. Grassland BGBC error was mapped
from the error of the AGBC estimates and the respective root-to-shoot ratios.Cropland BGBC

was again estimated from crop-specific yields and morphological parameters (Online-only Table
2) following Wolf et al.21 and Eq. 8where y is the crop’s yield (Mg ha−1), r is the root-to-shoot
ratio of the crop, and h is its harvest index. Here again we assume that 2.5% of all harvested
biomass is lost between the field and farmgate and that root biomass is 44% C, following Wolf
et al.21. BGBC error was mapped from the error of the 2000-to-2010 ANPP correction for BGBC

allocation as described above for cropland AGBC.The AGBC and BGBC maps were harmonized separately
following the same general schema (Fig. 3). Given that our harmonized woody biomass map contains
biomass estimates for grid cells in which any amount of tree cover was detected at the subpixel
level (see section 1.1), we conserved its estimates regardless of the landcover reported by
the 2010 CCI map in order to more fully account for woody biomass in non-forested areas17.

We then used the MODIS continuous vegetation fields percent tree cover map for 201063 to allocate
additional biomass density associated with the most probable herbaceous cover (grass or crop)
to each grid cell in quantities complementary to that of the grid cell’s fractional tree cover
estimate (Eq. 9)where μT is the total biomass estimate of a grid cell, μw is the woody biomass
estimate for the grid cell, μh is its herbaceous biomass estimate, and q is the MODIS fractional

tree cover of the grid cell. Since MODIS tree cover estimates saturate at around 80%64, we
linearly stretched values such that 80% was treated as complete tree cover (100%). Moreover,
we acknowledge that percent cover can realistically exceed 100% when understory cover is considered
but we were unable to reasonably determine the extent of underlying cover from satellite imagery.
As such, our approach may underestimate the contribution of herbaceous C stocks in densely

forested grid cells. The most likely herbaceous cover type was determined from the CCI Landcover
2010 map, which we aggregated into two “likely herbaceous cover” classes – grass or crop –
based on the assumed likelihood of cropland in each CCI class (Online-only Table 1). However,
due to inherent classification error in the native CCI Landcover map, when determining the
herbaceous biomass contribution we weighted the relative allocation of crop and grass biomass

to a given grid cell based on the probability of correct classification by the CCI map (i.e.
“user’s accuracy”, Table 6) of the most probable herbaceous class (\({p}_{i}\)) such that
μh can be further expressed as (Eq. 10)where μi is the predicted biomass of the most probable
herbaceous class, and μj is that of the less probable class.Decision tree used to allocate
landcover-specific biomass estimates to each grid cell of our harmonized global products.The

uncertainty of a grid cell’s total AGBC or BGBC estimate (\({\sigma }_{T}\)) was determined
and mapped from that of its components (\({\mu }_{w}\,{\rm{and}}\,{\mu }_{h}\)) by summation
in quadrature which can be simplified as (Eq. 11)where \({\sigma }_{w}\) is the error of the
grid cell’s estimated μw, \({\sigma }_{h}\) is the error of its estimated μh, and \({\sigma
}_{q}\) is the error of its q. Here, \({\sigma }_{h}\) can be further decomposed and expressed

as Eq. 12 to account for the accuracy weighted allocation procedure expressed previously (Eq.
10)where \({\sigma }_{i}\) is the error of the estimated biomass density of the most probable
herbaceous class, \({\delta }_{i}\) is the estimated standard deviation of that class’s Bernoulli
probability (p; Eq. 7), and \({\sigma }_{j}\) is the error of the estimated biomass density
of the less probable herbaceous subclass.Exceptions to the above schema were made in the tundra

and boreal biomes – as delineated by the RESOLVE Ecoregions 2017 biome polygons65 – where
thematic overlap was likely between the woody and tundra plant biomass maps. A separate set
of decision rules (Fig. 3) was used to determine whether grid cells in these biomes were to
be exclusively allocated the estimate of the tundra plant map or that of the fractional allocation
procedure described above. In general, any land in these biomes identified as sparse landcover

by the CCI landcover map (Online-only Table 1) was assigned the tundra vegetation estimate.
In addition, lands north of 60° latitude with less than 10% tree cover or where the tundra
AGBC estimate exceeded that of the woody AGBC estimate were also exclusively assigned the
tundra vegetation estimate. Lands north of 60° latitude not meeting these criteria were assigned
the woody value with the additional contribution of grass.Subtle numerical artefacts emerged

from the divergent methodologies employed north and south of 60°N latitude. These were eliminated
by distance weighting grid cells within 1° of 60°N based on their linear proximity to 60°N
and then averaging estimates such that values at or north of 61°N were exclusively based on
the northern methodology, those at 60°N were the arithmetic average of the two methodologies
and those at or south of 59°N were exclusively based on the southern methodology. This produced

a seamless, globally harmonized product that integrates the best remotely sensed estimates
of landcover-specific C density. Water bodies identified as class “210” of the CCI 2010 landcover
map were then masked from our final products.Data layers (n = 4, Table 7) for the maps of
AGBC and BGBC density (Fig. 4) as well as their associated uncertainty maps which represent
the combined standard error of prediction (Fig. 5) are available as individual 16-bit integer

rasters in GeoTiff format. All layers are natively in a WGS84 Mercator projection with a spatial
resolution of approximately 300 m at the equator and match that of the ESA CCI Landcover Maps37.
Raster values are in units megagrams C per hectare (MgC ha−1) and have been scaled by a factor
of ten to reduce file size. These data are accessible through the Oak Ridge National Laboratory
(ORNL) DAAC data repository (https://doi.org/10.3334/ORNLDAAC/1763)66. In addition, updated

and/or derived vegetation-specific layers that were used to create our harmonized 2010 maps
are available as supplemental data on figshare67.Globally harmonized maps of above and belowground
living biomass carbon densities. (a) Aboveground biomass carbon density (AGBC) and (b) belowground
biomass carbon density (BGBC) are shown separately. Maps have been aggregated to a 5 km spatial
resolution and reprojected here for visualization.Uncertainty of grid cell level above and

belowground biomass carbon density estimates. Uncertainty is shown here as the coefficient
of variation (%; standard error layer divided by mean estimate layer) of estimated AGBC (a)
and BGBC (b) densities after harmonization. Maps have been aggregated to a 5 km spatial resolution
and projected for visualization.Our harmonized products rely almost exclusively upon maps
and models that have been rigorously validated by their original producers and were often

accompanied by constrained uncertainty estimates. Throughout our harmonization procedure,
we strived to conserve the validity of each of these products by minimizing the introduction
of additional error and by tracking any introductions, as described above, such that the final
error layers represent the cumulative uncertainty of the inputs used. Ground truth AGB and
BGB data are almost always collected for individual landcover types. Consequently, we are

unable to directly assess the validity of our integrated estimates beyond their relationships
to individual landcover-specific estimates and the extents to which they were modified from
their original, previously-validated form prior to and during our harmonization procedure.Temporal
and spatial updates made to existing landcover-specific maps of non-tree AGB resulted in relatively
small changes to their predictions. For example, we used numerically calibrated MODIS imagery

to extend the Landsat-based tundra plant AGB model beyond its native extent (the North Slope
of Alaska) to the pan-Arctic region since neither a comparable model nor a consistent Landsat
time series were available for this extent. We assessed the effects of these assumptions by
comparing our predictions for the North Slope with those of the original map18 (Fig. 6a).
Both positive and negative discrepancies exist between ours and the original, though these

rarely exceed ±2 MgC ha−1 and no discernibly systematic bias was evident.Differences between
landcover-specific AGBC estimates from the original published maps and the modified versions
used as inputs to create the 2010 harmonized global maps. Tundra vegetation AGBC (a) is compared
to the Landsat-based map of Berner et al.45 for the north slope of Alaska after converting
it to units MgC ha−1. Here, the comparison map was subsequently aggregated to a 1 km resolution

and reprojected for visualization. Grassland AGBC (b) is compared to the AVHRR-based map of
Xia et al.19 which represents the average estimate between 1982–2006. For visualization, the
map was aggregated to a 5 km resolution and subsequently reprojected after being masked to
MODIS IGBP grasslands in the year 200685 following Xia et al.19. As such, this map does not
necessarily represent the spatial distribution of grid cells in which grassland estimates

were used. Cropland AGBC (c) is compared to the original circa 2000 estimates to assess the
effects of the 2000-to-2010 correction. The map is masked to the native extent of the combined
yield maps and aggregated to a 5 km resolution for visualization. For all maps, negative values
indicate that our circa 2010 estimates are lower than those of the earlier maps while positive
values indicate higher estimates.Our updated map of grassland biomass carbon in the year 2010

was similarly made by applying the original AVHRR-based model to calibrated MODIS imagery.
This too resulted in only subtle changes to the original biomass map (Fig. 6b) that were rarely
in excess of 0.5 MgC ha−1. In most areas, our estimates were higher than those of Xia et al.19
who mapped the mean AGBC density between 1986 and 2006. Most of these elevated estimates corresponded
with areas in which significant NDVI increases (“greening”) have been reported while notably

lower estimates in the Argentine Monte and Patagonian steppe biomes of southern South America,
likewise, correspond with areas of reported “browning”68,69. Both greening and browning trends
are well documented phenomena and have been linked to climatic changes70. Moreover, we further
compared AGBC estimates from both the original Xia et al.19 map and our 2010 update to AGBC
field measurements coordinated by the Nutrient Network that were collected from 48 sites around

the world between 2007 and 200949. The RMSE (0.68 MgC ha−1) of our updated map was 10% less
that of the Xia et al. map for sites with less than 40% tree cover. Likewise, our 2010 estimates
were virtually unbiased (bias = −0.01 MgC ha−1) in comparison to the Xia map (bias = 0.25
MgC ha−1). While still noisy, these results suggest that our temporal update improved the
overall accuracy of estimated grassland AGBC.Finally, cropland biomass carbon maps were also

updated from their native epoch (2000) to 2010 using pixel-wise rates of MODIS ANPP change
over a ten-year period. While MODIS ANPP may be a poor snapshot of crop biomass in a single
year, we assumed that its relative change over time reflects real physiological shifts affecting
the cropland C cycle. This correction also resulted in only small differences that rarely
exceeded ±2 MgC ha−1 and that, spatially, correspond well with observed declines in the yields

of select crops that have been linked to climate change71,72 (Fig. 6c). Nonetheless, updated
global yield maps comparable to those available for 2000 would greatly improve our understanding
of the interactions between climate change, crop yields, and C dynamics.Belowground biomass
is notoriously difficult to measure, model, and also to validate. We accounted for the reported
uncertainty of nearly every variable considered when estimating belowground biomass and pixel-level

uncertainty, but we were unable to perform an independent validation of our harmonized estimates
at the pixel level due to a paucity of globally consistent field data. To complete such a
task, a globally orchestrated effort to collect more BGB samples data across all vegetation
types is needed.Given this lack of data, we instead compared the estimated uncertainty of
our BGBC maps to that of our AGBC estimates to infer the sources of any divergence (Fig. 5).

As expected, our cumulative BGBC uncertainty layer generally reveals greater overall uncertainty
than our AGBC estimates, with BGBC uncertainty roughly twice that of AGBC throughout most
of the globe. The highest absolute uncertainty was found in biomass rich forests. Arid woodlands,
especially those of the Sahel and eastern Namibia, generally had the greatest relative BGBC
uncertainty, though their absolute uncertainty was quite small (generally less than 3 MgC

ha−1). Here, biomass estimates of sparse woody vegetation were primarily responsible for heightened
relative uncertainty. High relative and absolute BGBC uncertainty were also associated with
predictions in select mountainous forests (e.g. east central Chile) as well as forested areas
in and around cities. These patterns were largely driven by AGB uncertainty in the GlobBiomass
product.The GlobBiomass global woody AGB map produced by Santoro et al.30 comprises the backbone

of our integrated products and, with few exceptions, remains largely unchanged in our final
AGBC map. The native version of the GlobBiomass map is accompanied by an error layer describing
the uncertainty of each pixel’s biomass estimate and this too forms the core of our integrated
uncertainty layers. In areas with tree cover, the global average error of GlobBiomass estimates
is 39 Mg ha−1 or 50% with greater relative uncertainty in densely forested areas, along the

margins of forested expanses like farm fields and cities, and in similar areas with sparse
tree cover.Adding additional grass or crop biomass in complementary proportion to a grid cell’s
tree cover often did not exceed the estimated error of the original GlobBiomass map (Fig.
7). Grid cells exceeding GlobBiomass’s native uncertainty comprise less than 40% of its total
extent. Exceptions were primarily found in grassland and cropland dominated regions where

tree cover was generally sparse, and, consequently, the herbaceous biomass contribution was
relatively high. Even so, the absolute magnitude of these additions remains somewhat small
(less than 2.3 MgC ha−1 for grassland and 15 MgC ha−1 for cropland).Differences between the
final harmonized AGBC map and GlobBiomass AGBC. GlobBiomass AGB was aggregated to a 300 m
spatial resolution and converted to C density prior to comparison. Negative values indicate

areas where the new map reports lower values than GlobBiomass while positive value denote
higher estimates.Larger deviations from GlobBiomass were also present in areas of both dryland
Africa and the Arctic tundra biome, where we used independent layers to estimate woody biomass.
In African drylands, GlobBiomass likely underestimates woody biomass by adopting the conservative
FAO definition (DBH > 10 cm), which implicitly omits the relatively small trees and shrubs

that are common to the region. The Bouvet map of Africa that we used to supplement these estimates
is not bound by this constraint, was developed from region-specific data, and predicts substantially
higher AGB density throughout much of its extent with comparatively high accuracy (RMSE =
17.1 Mg ha−1)35.GlobBiomass also included sporadic biomass estimates throughout much of the
Arctic tundra biome. Trees are generally scarce throughout this biome, which is instead dominated

by dwarf shrubs and herbaceous forbs and graminoids, so given GlobBiomass’s adherence to FAO
guidelines, its predictions here may be spurious. We thus prioritized the estimates of the
independent model developed specifically to collectively predict biomass of both woody and
herbaceous tundra vegetation. These estimates were generally higher than GlobBiomass but agreed
well with independent validation data from North America (RMSE = 2.9 Mg ha−1)18.While far

from a perfect comparison, the only other map to comprehensively report global biomass carbon
density for all landcover types is the IPCC Tier-1 map for the year 2000 by Ruesch and Gibbs28.
As previously described, this map was produced using an entirely different method (“stratify
and multiply”) and distinct data sources23 and represents an earlier epoch. However, the map
is widely used for myriad applications, and it may thus be informative to assess notable differences

between it and our new products.Ruesch and Gibbs28 report total living C stocks of 345 petagrams
(PgC) in AGBC and 133 PgC in BGBC for a total of 478 PgC, globally. Our estimates are lower
at 287 PgC and 122 PgC in global AGBC and BGBC, respectively, for a total of 409 PgC in living
global vegetation biomass. Herbaceous biomass in our maps comprised 9.1 and 28.3 PgC of total
AGBC and BGBC, respectively. Half of all herbaceous AGBC (4.5 PgC) and roughly 6% of all herbaceous

BGBC (1.7 PgC) was found in croplands. Moreover, we mapped 22.3 and 6.1 PgC, respectively,
in the AGB and BGB of trees located within the cropland extent. These trees constituted roughly
7% of all global biomass C and are likely overlooked by both the Ruesch and Gibbs map28 and
by remotely sensed forest C maps that are masked to forested areas. Zomer et al.17 first highlighted
this potential discrepancy in the Ruesch and Gibbs map28 when they produced a remarkably similar

estimate of 34.2 Pg of overlooked C in cropland trees using Tier-1 defaults. However, their
estimates were assumed to be in addition to the 474 PgC originally mapped by Ruesch and Gibbs28.
Here, we suggest that the 28.4 PgC we mapped in cropland trees is already factored into our
409 PgC total.Our AGBC product predicts substantially less biomass C than Ruesch and Gibbs28
throughout most of the pantropical region and, to a lesser extent, southern temperate forests

(Fig. 8a). This pattern has been noted by others comparing the Ruesch and Gibbs map28 to other
satellite-based biomass maps73 and may suggest that the IPCC default values used to create
it23 are spatially biased. In addition, well-defined areas of high disagreement emerge in
Africa that directly correspond with the FAO boundaries of the “tropical moist deciduous forest”
ecofloristic zone and suggest that this area, in particular, may merit critical review. Moreover,

the opposite pattern is observed in this same ecofloristic zone throughout South America.
Our map also predicts greater AGBC throughout much of the boreal forest as well as in African
shrublands and the steppes of South America.Differences between the 2010 harmonized global
maps of above and belowground biomass carbon density and those of the IPCC Tier-1 product
by Ruesch and Gibbs for 2000. Comparisons of AGBC (a) and BGBC (b) maps are shown separately.

Negative values indicate that the circa 2010 estimates are comparatively lower while positive
values indicate higher estimates.We observed similar, though less pronounced discrepancies,
when comparing BGBC maps (Fig. 8b). Notably, our map predicts substantially more BGBC throughout
the tundra biome – a previously underappreciated C stock that has recently risen to prominance74
– the boreal forest, African shrublands and most of South America and Australia. However,

we predict less BGBC in nearly all rainforests (Temperate and Tropical). These differences
and their distinct spatial patterns correspond with the vegetation strata used to make the
IPCC Tier-1 map28 and suggest that the accuracy of the “stratify and multiply” method depends
heavily upon the quality of the referenced and spatial data considered. Inaccuracies in these
data may, in turn, lead to false geographies. Integrating, continuous spatial estimates that

better capture local and regional variation, as we have done, may thus greatly improve our
understanding of global carbon geographies and their role in the earth system.The error and
variance between our woody biomass estimates – when aggregated to the country level – and
comparable totals reported in the FRA were less for comparisons made against FRA estimates
generated using higher tier IPCC methodologies than for those based on Tier-1 approaches (Fig.

9). Across the board for AGBC, BGBC, and total C comparisons, the relative RMSE (RMSECV) of
our estimates, when compared to estimates generated using high tier methods, was roughly half
of that obtained from comparisons with Tier-1 estimates (Table 8). Likewise, the coefficient
of determination (R2) was greatest for comparisons with Tier-3 estimates. For each pool-specific
comparison (AGBC, BGBC, and total C), the slopes of the relationships between Tier-1, 2, and

3 estimates were neither significantly different from a 1:1 relationship nor from one another
(p > 0.05; ANCOVA). Combined, these results suggest that our maps lead to C stock estimates
congruent with those attained from independent, higher-tier reporting methodologies.Comparison
of woody biomass density estimates to corresponding estimates of the FAO’s FRA and the USFS’s
FIA. National woody AGBC totals derived from the woody components of our harmonized maps are

compared to national totals reported in the 2015 FRA62 (a) in relation to the IPCC inventory
methodology used by each country. Likewise, we derived woody AGBC totals for US states and
compared them to the corresponding totals reported by the 2014 FIA75 (b), a Tier-3 inventory.
We also show the additional effect of considering non-woody C – as is reported in our harmonized
maps – in light green. Similar comparisons were made between our woody BGBC estimates and

the corresponding estimates of both the FRA (c) and FIA (d). We further summed our woody AGBC
and BGBC estimates and compared them to the total woody C stocks reported by both the FRA
(e) and FIA (f).To explore this association at a finer regional scale, we also compared our
woody C estimates to the United States Forest Service’s Forest Inventory Analysis75 (FIA)
and found similarly strong congruence for AGBC and Total C stocks but subtle overestimates

for BGBC (Fig. 9). The FIA is a Tier-3 inventory of woody forest biomass C stocks that is
based on extensive and statistically rigorous field sampling and subsequent upscaling, We
used data available at the state level for the year 2014 – again, the only year in which we
could obtain data partitioned by AGBC and BGBC. Like our FRA comparison, we found a tight
relationship between our woody AGBC totals and those reported by the FIA (Fig. 9b; RMSECV

= 25.7%, R2 = 0.960, slope = 1.10, n = 48). Our woody BGBC estimates, though, were systematically
greater than those reported by the FIA (Fig. 9d; RMSECV = 86.4%, R2 = 0.95, slope = 1.51,
n = 48). This trend has been noted by others27 and suggests that the global model that we
used to estimate woody BGBC may not be appropriate for some finer scale applications as is
foretold by the elevated uncertainty reported in our corresponding uncertainty layer (Fig.

5b). Our total woody C (AGBC + BGBC) estimates (Fig. 9f), however, agreed well with the FIA
(RMSECV = 34.1%, R2 = 0.961, slope = 1.17, n = 48) and thus reflect the outsized contribution
of AGBC to the total woody C stock. When the contribution of herbaceous C stocks is further
added to these comparisons, our stock estimates intuitively increase in rough proportion to
a state’s proportional extent of herbaceous cover. The effect of this addition is particularly

pronounced for BGBC estimates due to the large root-to-shoot ratios of grassland vegetation.The
relative congruence of our results with higher-tier stock estimates suggests that our maps
could be used to facilitate broader adoption of higher-tier methods among countries currently
lacking the requisite data and those seeking to better account for C in non-woody biomass.
This congruence spans a comprehensive range of biophysical conditions and spatial scales ranging

from small states to large nations. Moreover, a recent study suggests that the fidelity of
the underlying GlobBiomass AGB map may extend to even finer scales31. While our BGBC estimates
may differ from some fine-scale estimates (Fig. 9d), their tight agreement with high tier
BGBC totals at the national level (Fig. 9c) suggests that they may still be well suited for
many national-scale C inventories – especially for countries lacking requisite high tier data.

Use of our maps is unlikely to introduce error in excess of that currently implicit in Tier-1
estimates. Credence, though, should be given to the associated uncertainty estimates. To facilitate
wider adoption of higher-tier methodologies, our maps could be used to derive new, region-specific
default values for use in Tier-2 frameworks76 or to either represent or calibrate 2010 baseline
conditions in Tier-3 frameworks. In so doing, inventories and studies alike could more accurately

account for the nuanced global geographies of biomass C.These maps are intended for global
applications in which continuous spatial estimates of live AGBC and/or BGBC density are needed
that span a broad range of vegetation types and/or require estimates circa 2010. They are
loosely based upon and share the spatial resolution of the ESA CCI Landcover 2010 map37, which
can be used to extract landcover specific C totals. However, our products notably do not account

for C stored in non-living C pools like litter or coarse woody debris, nor soil organic matter,
though these both represent large, additional ecosystem C stocks77,78,79. Our maps are explicitly
intended for global scale applications seeking to consider C in the collective living biomass
of multiple vegetation types. For global scale applications focused exclusively on the C stocks
of a single vegetation type, we strongly encourage users to instead use the respective input

map or model referenced in Table 1 to avoid potential errors that may have been introduced
by our harmonization procedure. For AGB applications over smaller extents, users should further
consider whether locally specific products are available. If such maps are not available and
our maps are considered instead, credence should be given to their pixel-level uncertainty
estimates. As mentioned above, the biomass of shrublands was only explicitly accounted for

in Africa and the Arctic tundra, since neither broad-scale maps nor models generalizable to
other areas were available in the existing literature. As such, we caution against the use
of our maps outside of these areas when shrubland biomass is of particular interest or importance.
Moreover, in contrast to the estimates for all other vegetation types considered, which we
upscaled to a 300 m resolution, cropland C estimates were largely based on relatively coarse

8 km resolution data that were downscaled using bilinear resampling to achieve a 300 m spatial
resolution. As such, these estimates may not adequately capture the underlying finer-scale
spatial variation and should be interpreted with that in mind. Likewise, we reiterate that
some BGBC estimates may differ from locally derived Tier-3 estimates, and attention should
thus be given to our reported pixel-level uncertainty for all applications. Finally, our maps

should not be used in comparison with the IPCC Tier-1 map of Ruesch and Gibbs (2008) to detect
biomass change between the two study periods due to significant methodological differences
between these products.Cropland biomass maps were created in the R statistical computing environment80.
All other coding was done in Google Earth Engine81 (GEE), wherein our workflow consisted of
18 interconnected scripts. All code can be found on GitHub (https://github.com/sethspawn/globalBiomassC)

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all the data producers, without whom this work would not be possible. We especially thank
Maurizio Santoro et al., Alexandre Bouvet et al., Jiangzhou Xia et al., Logan T. Berner et
al., Chad Monfreda et al., and Julie Wolf et al. whose AGB estimates comprise the core of
our harmonized products and, in many cases, whose feedback greatly improved the quality of
their inclusion. We are also grateful to the thoughtful feedback of three anonymous reviewers

whose suggestions greatly improved the quality of our products and the clarity of our manuscript.
Funding for this project was generously provided by the David and Lucile Packard Foundation
and the National Wildlife Federation.Department of Geography, University of Wisconsin-Madison,
Madison, WI, USASeth A. Spawn, Clare C. Sullivan & Holly K. GibbsCenter for Sustainability
and the Global Environment (SAGE), Nelson Institute for Environmental Studies, University

of Wisconsin-Madison, Madison, WI, USASeth A. Spawn, Clare C. Sullivan, Tyler J. Lark & Holly
K. GibbsYou can also search for this author in PubMed Google ScholarYou can also search for
this author in PubMed Google ScholarYou can also search for this author in PubMed Google ScholarYou
can also search for this author in PubMed Google ScholarS.A.S. designed the harmonization
procedure, compiled and standardized individual biomass layers, conducted all mapping, and

led manuscript development. C.C.S., T.J.L. and H.K.G. assisted with conceptualization, and
manuscript development.Correspondence to Seth A. Spawn.The authors declare no competing interests.Publisher’s
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(MODIS) on NASA’s Terra satellite between January and July 2023.In the January 22 image (left),
water was coursing through seasonally dry channels of the Georgina River and Eyre Creek following
weeks of heavy rains in northern Queensland. By April 21 (middle), floodwaters had reached
further downstream after another intense period of precipitation in March. This scene shows
that water had filled in some of the north-northwest trending ridges that are part of a vast

fossil landscape of wind-formed dunes, while vegetation had emerged in wet soil upstream.
Then by July 26 (right), the riverbed had filled with even more vegetation.The Georgina River
and Eyre Creek drain approximately 210,000 square kilometers (81,000 square miles), nearly
the area of the United Kingdom. Visible in the lower part of the images, the lake gets refreshed
about every three years; when it reaches especially high levels, it may take 18 months to

2 years to dry up. Two smaller neighboring lakes flood seasonally. These three lakes and surrounding
floodplains support hundreds of thousands of waterbirds and are designated as an Important
Bird Area.Seasonal flooding is a regular occurrence in these desert river systems. However,
the events of the 2022-2023 rainy season stood out in several ways. They occurred while La
Niña conditions were in place over the tropical Pacific Ocean. (The wettest seasons in northern

Australia have all occurred during La Niña years, according to Australia’s Bureau of Meteorology.)
In addition, major rains occurring in succession, as was the case with the January and March
events, have the overall effect of prolonging floods. That’s because vegetation that grows
after the first event slows down the pulse of water that comes through in the next rain event.The
high water has affected both local communities and ecosystems. Floods have inundated cattle

farms and isolated towns on temporary islands. At the same time, they are a natural feature
of the “boom-and-bust” ecology of Channel Country, providing habitat and nutrients that support
biodiversity.NASA Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS
LANCE and GIBS/Worldview. Story by Lindsey Doermann.View this area in EO ExplorerRepeated
heavy rains in Australia set off waves of new growth across Channel Country.Image of the Day

for August 7, 2023 Image of the Day Land Water View more Images of the Day: Floods The waves
off the coast of Teahupo’o can heave a crushing amount of water toward the shore and onto
unlucky surfers. Image of the Day Water Waves of heavy rainfall left towns and farmland under
water in October 2022. Image of the Day Water Floods Acquired February 26, 2011, and February
5, 2011, these false-color images show the impact of heavy rains in marshy areas southeast

of Georgetown, Guyana. Land Floods August 25, 2023JPEGSeptember 18, 2023JPEGAugust 25, 2023September
18, 2023August 25, 2023JPEGSeptember 18, 2023JPEGSeptember 18, 2023JPEGHeavy rain from a cyclone
in the Mediterranean inundated cities along the northeastern coast of Libya in early September
2023, causing thousands of deaths. The port city of Derna (Darnah), home to about 90,000 people,
was one of the worst hit by the storm and suffered extensive flooding and damage. On September

10 and 11, over 100 millimeters (4 inches) of rain fell on Derna. The city lies at the end
of a long, narrow valley, called a wadi, which is dry except during the rainy season. Floods
triggered two dams along the wadi to collapse. The failure of the second dam, located just
one kilometer inland of Derna, unleashed 3- to 7-meter-high floodwater that tore through the
city. According to news reports, the flash floods destroyed roads and swept entire neighborhoods

out to sea. The images above show the city before and after the storm. The image on the right,
acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9 on September 18, shows eroded
banks of Wadi Derna near where it meets the Mediterranean. Water just off the coast appears
muddier than in the image on the left, which shows the same area on August 25 and was acquired
by Landsat 8. Preliminary estimates by the United Nations Satellite Center (UNOSAT) indicate

that 3,100 buildings in Derna were damaged by rushing water. According to the UN International
Organization for Migration (IOM), about 40,000 people in the country were displaced by the
storm, and 30,000 of those were displaced from Derna. Tropical-like cyclones in the Mediterranean,
or “medicanes,” develop only once or twice a year, according to NOAA, and typically form in
autumn. According to meteorologists at Yale Climate Connections, this storm was the deadliest

in Africa’s recorded history. A recent assessment by scientists at World Weather Attribution
estimated that precipitation received by the region was a one-in-300 to one-in-600-year event.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological
Survey. Story by Emily Cassidy.View this area in EO ExplorerFlash floods in the port city
destroyed roads and swept neighborhoods out to sea.Image of the Day for September 21, 2023

Image of the Day Land Water Floods Human Presence View more Images of the Day:The melting
of frozen rivers and snowpack, and the heavy rains of late spring and summer, can send rivers
out of their banks.A Mediterranean cyclone contributed to deadly flooding along the country’s
coastline. Image of the Day Land Water Floods Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence A stalled storm

dropped three feet of rain over four days on the Thessaly region, triggering extensive flooding.
Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential downpours
in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land Floods
Human Presence July 2002 - June 2022JPEGThe deep-blue sea is turning a touch greener. While
that may not seem as consequential as, say, record warm sea surface temperatures, the color

of the ocean surface is indicative of the ecosystem that lies beneath. Communities of phytoplankton,
microscopic photosynthesizing organisms, abound in near-surface waters and are foundational
to the aquatic food web and carbon cycle. This shift in the water’s hue confirms a trend expected
under climate change and signals changes to ecosystems within the global ocean, which covers
70 percent of Earth’s surface. Researchers led by B. B. Cael, a principal scientist at the

U.K.’s National Oceanography Centre, revealed that 56 percent of the global sea surface has
undergone a significant change in color in the past 20 years. After analyzing ocean color
data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua
satellite, they found that much of the change stems from the ocean turning more green. The
map above highlights the areas where ocean surface color changed between 2002 and 2022, with

darker shades of green representing more-significant differences (higher signal-to-noise ratio).
By extension, said Cael, “these are places we can detect a change in the ocean ecosystem in
the last 20 years.” The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters, where the data are naturally
very noisy. The black dots on the map indicate the area, covering 12 percent of the ocean’s

surface, where chlorophyll levels also changed over the study period. Chlorophyll has been
the go-to measurement for remote sensing scientists to gauge phytoplankton abundance and productivity.
However, those estimates use only a few colors in the visible light spectrum. The values shown
in green are based on the whole gamut of colors and therefore capture more information about
the ecosystem as a whole. A long time series from a single sensor is relatively rare in the

remote sensing world. As the Aqua satellite was celebrating its 20th year in orbit in 2022—far
exceeding its design life of 6 years—Cael wondered what long term trends could be discovered
in the data. In particular, he was curious what might have been missed in all the ocean color
information it had collected. “There’s more encoded in the data than we actually make use
of,” he said. By going big with the data, the team discerned an ocean color trend that had

been predicted by climate modeling, but one that was expected to take 30-40 years of data
to detect using satellite-based chlorophyll estimates. That’s because the natural variability
in chlorophyll is high relative to the climate change trend. The new method, incorporating
all visible light, was robust enough to confirm the trend in 20 years. At this stage, it is
difficult to say what exact ecological changes are responsible for the new hues. However,

the authors posit, they could result from different assemblages of plankton, more detrital
particles, or other organisms such as zooplankton. It is unlikely the color changes come from
materials such as plastics or other pollutants, said Cael, since they are not widespread enough
to register at large scales. “What we do know is that in the last 20 years, the ocean has
become more stratified,” he said. Surface waters have absorbed excess heat from the warming

climate, and as a result, they are less prone to mixing with deeper, more nutrient-rich layers.
This scenario would favor plankton adapted to a nutrient-poor environment. The areas of ocean
color change align well with where the sea has become more stratified, said Cael, but there
is no such overlap with sea surface temperature changes. More insights into Earth’s aquatic
ecosystems may soon be on the way. NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem)

satellite, set to launch in 2024, will return observations in finer color resolution. The
new data will enable researchers to infer more information about ocean ecology, such as the
diversity of phytoplankton species and the rates of phytoplankton growth. NASA Earth Observatory
image by Wanmei Liang, using data from Cael, B. B., et al. (2023). Story by Lindsey Doermann.Two
decades of satellite measurements show that the sea surface is shading toward green.Image

of the Day for October 2, 2023 Image of the Day Life Water View more Images of the Day:Datasets
from the Sentinel-6 Michael Freilich satellite will build upon three decades of sea level
measurements. Image of the Day Heat Water Remote Sensing Image of the Day Life Water Image
of the Day Water The use of plastic on farms has become so common in recent decades that there
there’s a term for it—plasticulture. Image of the Day Human Presence August 16, 2023JPEGThe

Canary Islands were at the center of a mélange of natural events in summer 2023. The Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this assemblage
of phenomena off the coast of Africa on August 16, 2023.In the center of the scene, smoke
is seen rising from a wildfire burning on Tenerife in the Canary Islands. The blaze started
amid hot and dry conditions on August 15 in forests surrounding the Teide Volcano. Authorities

issued evacuation orders to five villages, and responders focused on containing the fire’s
spread and protecting residential areas near the coast, according to news reports. Other fires
have burned on the Canary Islands this summer, including on La Palma in July.To the west,
a swirling cloud moves across the Atlantic. Cloud vortices appear routinely downwind of the
Canary Islands—sometimes in great abundance—and are produced when the tall volcanic peaks

disrupt the air flowing past them.Elsewhere in the atmosphere, dust from the Sahara Desert
was lofted out over the ocean. The river of dust crossing the Atlantic was more pronounced
in previous days, when it reached islands in the Caribbean. Traveling on the Saharan Air Layer,
dust sometimes makes it even further west toward Central America and the U.S. states of Florida
and Texas.To round out the list, the patch of bright blue off the Moroccan coast is most likely

a bloom of phytoplankton. While the exact cause and composition of the bloom cannot be determined
from this image, mineral-rich desert dust has been shown to set off bursts of phytoplankton
growth.In addition to the Earth’s processes seen here, one remote sensing artifact is present.
A diagonal streak of sunglint makes part of this scene appear washed out. Sunglint, an effect
that occurs when sunlight reflects off the surface of the water at the same angle that a satellite

sensor views it, is also the reason for the light-colored streaks trailing off the islands.NASA
Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Lindsey Doermann.View this area in EO ExplorerAn assortment of natural phenomena
visible from space appeared together in one image.Image of the Day for August 17, 2023 Image
of the Day Atmosphere Land Water View more Images of the Day:Flights were grounded as visibility

was severely hampered by a Calima event. Image of the Day Atmosphere Land Dust and Haze Human
Presence In one frame International Space Station astronauts were able to capture the evolution
of fringing reefs to atolls. As with the Hawaiian Islands, these volcanic hot spot islands
become progressively older to the northwest. As these islands move away from their magma sources
they erode and subside. Image of the Day Land Water The dry, volcanic terrain of this Canary

Island is suitable for lichen and crops … and for training astronauts. Image of the Day Land
The event, known locally as “la calima,” turned skies orange and degraded air quality in Gran
Canaria and neighboring islands. Image of the Day Atmosphere Land Dust and Haze July 17, 2023JPEGFour
funnel-shaped estuarine inlets, collectively known as Rías Baixas, line the coast of Galicia,
in northwest Spain. The nutrient-rich water in these inlets supports a wealth of marine life,

making the Galicia coast one of the most productive places for aquaculture.On July 17, 2023,
the Operational Land Imager-2 (OLI-2) on Landsat 9, acquired this image of the Rías de Arousa
(Arousa estuary), the largest and northernmost of the inlets. Small dots skirt the coasts
of the embayment. In most cases, these dots are rectangular rafts designed for raising bivalves
like mussels. Buoys keep the lattice mussel rafts afloat on the surface of the water, and

hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings
colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area

between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth
Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story

by Emily Cassidy. Buoys keep the lattice mussel rafts afloat on the surface of the water,
and hundreds of ropes are suspended into the water column from each structure. Mussels attach
to the ropes and filter feed on phytoplankton and other suspended organic particles. The rafts
allow for high yields of mussels in a small area of the water. The Rías Baixas are on the
northern end of the Canary current and are in a major upwelling zone. Upwelling, which brings

colder, nutrient-rich water up from the bottom of the ocean, typically occurs in this area
between April and October. Much of the mussel production in the Rías Baixas occurs during
this time, as the mollusks filter feed on nutrients and plentiful phytoplankton supported
by upwelling. Spain is the top mussel producing country in the world. Rías de Arousa alone
contains over 2,400 mussel rafts, producing about 40 percent of Europe’s mussels. NASA Earth

Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Story
by Emily Cassidy.View this area in EO ExplorerThe estuarine inlets of Spain’s Galicia coast
are some of the most productive places to grow mussels.Image of the Day for September 19,
2023 Image of the Day Water Human Presence View more Images of the Day: Dust and Haze This
image shows Tropical Cyclones Eric and Fanele near Madagascar on January 19, 2009. Atmosphere

Water Severe Storms This natural-color image shows Saharan dust forming an S-shaped curve
off the western coast of Africa, and passing directly over Cape Verde. Atmosphere Land Dust
and Haze Acquired March 8, 2010, this true-color image shows two icebergs, Iceberg B-09B and
an iceberg recently broken off the Mertz Glacier, floating in the Southern Ocean, just off
the George V Coast. Water Snow and Ice Sea and Lake Ice May 18, 2023JPEGSeptember 7, 2023JPEGMay

18, 2023September 7, 2023May 18, 2023JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter going
dry in 2018, Laguna de Aculeo has begun to refill. NASA satellites began to detect water pooling
in the parched lake in late-August, after an intense winter storm dropped as much as 370 millimeters
(15 inches) of rain on some parts of central Chile. The storm was fueled by an atmospheric
river and exacerbated by the rugged terrain in central Chile.When the Operational Land Imager-2

(OLI-2) on Landsat 9 acquired this image (right) on September 7, 2023, Laguna de Aculeo covered
about 5 square kilometers (2 square miles) to a depth of roughly 1 meter (3 feet). The other
image (left) shows the dried water body on May 18, 2023, before the wet winter weather arrived.
Although it has refilled somewhat, water spans only half the area it did up to 2010 and contains
a quarter of the water volume, explained René Garreaud, an Earth scientist at the University

of Chile. Seasonal changes and the influx of water have led to widespread greening of the
landscape around the lake.Researchers have assessed that ongoing development and water use
in the nearby community of Paine, increasing water use by farmers and in homes and pools,
as well as several years of drought, likely contributed to the drawdown of the lake. Annual
rainfall deficits that averaged 38 percent between 2010 and 2018 likely played a large role,

according to one analysis from a team of researchers from the University of Chile.Before 2010,
the shallow water body was a popular haven for boaters, swimmers, and water skiers, but the
water hasn’t yet pooled up enough for swimmers or boaters to return. It is also unclear how
long the new water in Aculeo will persist. “Atmospheric rivers in June and August delivered
substantial precipitation along the high terrain and foothills that have giv­­en us a welcome

interruption to the drought,” Garreaud said. “But Aculeo is a small, shallow lagoon that can
fill up rapidly, and it's only partly filled. Bigger reservoirs and aquifers will take much
longer to recover.”NASA Earth Observatory images by Lauren Dauphin, using Landsat data from
the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe drought
in Chile isn’t over, but recent late-winter rains provided enough moisture for water to start

pooling up again.Image of the Day for September 16, 2023 Image of the Day Life Water View
more Images of the Day:Data from winter 2022-2023 show the greatest net gain of water in nearly
22 years, but groundwater levels still suffer from years of drought. Image of the Day Land
Water As a persistent drought drags on, water levels are dropping at a key reservoir that
supplies Santiago. Image of the Day Land Water A new web tool designed by NASA applied scientists

could help the tribe anticipate and respond to drought. Image of the Day Water Human Presence
Remote Sensing For more than 100 years, groups in the western United States have fought over
water. During the 1880s, sheep ranchers and cattle ranchers argued over drinking water for
their livestock on the high plains. In 1913, the city of Los Angeles began to draw water away
from small agricultural communities in Owen Valley, leaving a dusty dry lake bed. In the late

1950s, construction of the Glen Canyon Dam catalyzed the American environmental movement.
Today, farmers are fighting fishermen, environmentalists, and Native American tribes over
the water in the Upper Klamath River Basin. The Landsat 7 satellite, launched by NASA and
operated by the U.S. Geological Survey, documented an extreme drought in the area along the
California/Oregon border in the spring of 2001. Image of the Day Land Life September 16, 2023JPEGSeptember

10, 2021JPEGSeptember 16, 2023September 10, 2021September 16, 2023JPEGSeptember 10, 2021JPEGSeptember
10, 2021JPEGMonths of excessive heat and drought parched the Mississippi River in the summer
and early fall of 2023. In September, low water levels limited barge shipments downriver and
threatened drinking water supplies in some Louisiana communities, according to the Associated
Press.Water levels were especially low near Memphis, Tennessee. The images above show the

Mississippi River near Memphis on September 16, 2023 (left), compared to September 10, 2021
(right). The river was significantly slimmed down in 2023, exposing some of the river bottom.This
is the second year in a row drought has caused the river to fall to near-record lows at many
gauges. On September 26, 2023, the river level at a gauge in Memphis was -10.26 feet, close
to the record low level, -10.81 feet, measured at the same place on October 21, 2022. That

was the lowest level recorded there since the start of National Weather Service records in
1954. Water levels, or “gauge heights,” do not indicate the depth of a stream; rather, they
are measured with respect to a chosen reference point. That is why some gauge height measurements
are negative.Farther upstream, water levels at New Madrid, Missouri, have been around -5 feet—near
the minimum operating level—since early September 2023. Water levels on the Mississippi normally

decline in the fall and winter, and in 2022, the river did not get that low until mid-October.
September 26, 2023JPEGA hot, dry summer is the main reason water levels dropped so low in
2023. Across the globe, temperatures in summer 2023 were 1.2°C (2.1°F) warmer than average.
In the U.S., Louisiana and Mississippi experienced their hottest Augusts on record, according
to NOAA.The U.S. Drought Monitor map above—the product of a partnership between the U.S. Department

of Agriculture, the National Oceanic and Atmospheric Administration, and the University of
Nebraska-Lincoln—shows conditions during the week of September 20-26, 2023. The map depicts
drought intensity in progressive shades of orange to red. It is based on an analysis of climate,
soil, and water condition measurements from more than 350 federal, state, and local observers
around the country. NASA contributes measurements and models that aid the drought monitoring

effort.During that week, about 38 percent of the contiguous U.S. was experiencing drought.
Lack of precipitation and high temperatures over several months severely dried out soils in
states along the Mississippi River Valley. The Drought Monitor reported that 80 percent of
soils in Louisiana were dry (short or very short on water) as of September 24. And for most
states in the river valley, over 50 percent of topsoil was dry or very dry.Shallow conditions

along the river interrupted normal shipments of goods. According to the Associated Press,
barge companies reduced the weight carried in many shipments in September because the river
was not deep enough to accommodate their normal weight. Much of U.S. grain exports are transported
down the Mississippi, and according to AP, the cost of these shipments from St. Louis southward
has risen 77 percent above the three-year average. The lack of freshwater flowing into the

Gulf of Mexico has also allowed saltwater to make its way up the river and into some water
treatment plants in southern Louisiana, according to the Associated Press. Some parts of Plaquemines
Parish are under drinking water advisories and have relied on bottled water for cooking and
drinking since June.Significant rainfall would be needed to flush out saltwater in the river
in Plaquemines. According to the National Weather Service’s Lower Mississippi River Forecast

Center, the forecast does not look promising. If enough rainfall doesn’t arrive before mid-to-late
October, saltwater could make its way to New Orleans.NASA Earth Observatory images by Lauren
Dauphin, using Landsat data from the U.S. Geological Survey and data from the United States
Drought Monitor at the University of Nebraska-Lincoln. Story by Emily Cassidy.View this area
in EO ExplorerIn September, low water levels made it more challenging to ship goods down the

river and allowed a wedge of saltwater to move upstream.Image of the Day for October 1, 2023
Image of the Day Water Drought View more Images of the Day:Persistent dry conditions can affect
water resources, ecosystems, and agriculture.Severe drought is reducing the number of daily
passages on the transoceanic shipping route. Image of the Day Water Human Presence Prolonged
drought in Kansas set the stage for what may be one of the state’s smallest wheat harvests

in decades. Image of the Day Land Water Drought The most severe drought in 70 years of record
keeping threatens the Horn of Africa with famine. Image of the Day Land Water Drought Low
water levels are making it difficult to ship goods down the river and allowing a wedge of
saltwater to move upstream. Image of the Day Land Water Human Presence Remote Sensing September
25, 2023JPEGLake Winnipeg, the world’s 10th largest freshwater lake by surface area, has experienced

algae blooms at a regular occurrence at least since the 1990s. A bloom of blue-green algae
once again covered parts of the lake in September 2023. Located in Manitoba, Canada, the long
lake has a watershed that spans one million square kilometers (386,000 square miles), draining
some of Canada’s agricultural land. The lake consists of a large, deep north basin and a smaller,
comparatively shallow south basin. Swirls of algae filled the south basin of the lake on September

25, 2023, when the OLI-2 (Operational Land Imager-2) on Landsat 9 acquired this image. Around
this time, satellite observations analyzed by Environment and Climate Change Canada indicated
that algae covered about 8,400 square kilometers (3,200 square miles), or about a third of
the lake’s area.Blue-green algae, also known as cyanobacteria, are single-celled organisms
that rely on photosynthesis to turn sunlight into food. The bacteria grow swiftly when nutrients

like phosphorus and nitrogen are abundant in still water. The bloom pictured here may contain
blue-green algae, as well as other types of phytoplankton; only a surface sample can confirm
the exact composition of a bloom. Some cyanobacteria produce microcystin—a potent toxin that
can irritate the skin and cause liver and kidney damage.While algae are part of a natural
freshwater ecosystem, excess algae, particularly cyanobacteria, can be a nuisance to residents

and tourists using the lake and its beaches for fishing, swimming, and recreation. Beaches
in the south basin of Lake Winnipeg can get as many as 30,000 visitors a day during the summer
months. Water samples taken at Winnipeg Beach on the west shore found that cyanobacteria levels
were elevated in August, and visitors were advised to avoid swimming and fishing if green
scum was visible. The health of Lake Winnipeg has been in decline in recent decades. Between

1990 and 2000, phosphorous concentrations in the lake almost doubled and algae blooms proliferated,
both in terms of occurrence and extent. The major contributors to the influx of phosphorous
to the lake were increased agricultural activities in the watershed and a higher frequency
of flooding, which has increased runoff into the lake.Phosphorus concentrations are almost
three times higher in the south basin of Lake Winnipeg, compared to the north basin. A 2019

study using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument
on NASA’s Terra satellite found that the chlorophyll-a concentrations, which are used as a
measure of phytoplankton biomass, were on average more than twice as high in the south basin,
compared to the north. NASA Earth Observatory images by Wanmei Liang, using Landsat data from
the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerAn influx

of nutrients in recent decades has contributed to the proliferation of algae in the large
Canadian lake.Image of the Day for October 6, 2023 Image of the Day Water Water Color View
more Images of the Day:Floating, plant-like organisms reproduce abundantly when there are
sufficient nutrients, sunlight, and water conditions. Extreme blooms of certain species can
become harmful to marine animals and humans.Cyanobacteria covered over half of the surface

of Florida’s largest freshwater lake in mid-June 2023. Image of the Day Life Water Water Color
Nearly half of the lake was covered with blue-green algae in early July 2022. Image of the
Day Water Remote Sensing Water Color More than 40 years after the explosive eruption of Mount
St. Helens, relics from the blast continue to haunt a nearby lake. Image of the Day Water
Venezuela’s Lake Maracaibo is choking with oil slicks and algae. Image of the Day Life Water

Human Presence Remote Sensing October 8, 2022JPEGOctober 3, 2023JPEGOctober 8, 2022October
3, 2023October 8, 2022JPEGOctober 3, 2023JPEGOctober 3, 2023JPEGJuly through October fall
within the dry season in the western and northern Amazon rainforest, but a particularly acute
lack of rain during this period in 2023 has pushed the region into a severe drought.The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image (right) of the parched

Rio Negro in the Brazilian province of Amazonas near the city of Manaus on October 3, 2023.
On that date, the level of the river, the largest tributary of the Amazon River, had dropped
to 15.14 meters (50.52 feet), according to data collected by the Port of Manaus. For comparison,
the image on the left shows the same area on October 8, 2022, when the water level was 19.59
meters, a more typical level for October. Rio Negro water levels continued to drop in the

days after the image was collected, reaching a record low of 13.49 meters on October 17, 2023.Some
areas in the Amazon River’s watershed have received less rain between July and September than
any year since 1980, Reuters reported. The drought has been particularly severe in the Rio
Negro watershed in northern Amazonas, as well as parts of southern Venezuela and southern
Colombia.“Overall, this is a pretty unusual and extreme situation,” said René Garreaud, an

atmospheric scientist at the University of Chile. “The primary culprit exacerbating the drought
appears to be El Niño.” This cyclical warming of surface waters in the central-eastern Pacific
functions somewhat like a boulder in the middle of a stream, disrupting atmospheric circulation
patterns in ways that lead to wetter conditions over the equatorial Pacific and drier conditions
over the Amazon Basin.According to news outlets, the low river water levels on the Rio Negro

and other nearby rivers have disrupted drinking water supplies in hundreds of communities,
slowed commercial navigation, and led to fish and dolphin die-offs.Manaus, the capital and
largest city of the Brazilian state of Amazonas, is the primary transportation hub for the
upper Amazon, serving as an important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include chemical, ship, and electrical

equipment manufacturing.NASA Earth Observatory images by Wanmei Liang, using Landsat data
from the U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerThe water
level of the largest tributary of the Amazon River has hit a record low.Image of the Day for
October 18, 2023 Image of the Day Water Human Presence View more Images of the Day:The impact
of severe drought on the Negro River, a tributary of the Amazon River, and other rivers in

the basin is dramatically evident in this pair of images, which show that every body of water
has shrunk in 2010 compared to 2008. Image of the Day Atmosphere Land The volume of water
in New Mexico’s largest reservoir has dropped to historic lows due to drought and persistent
demand. Image of the Day Water Human Presence Acquired June 25, 2011, and June 22, 2010, these
false-color images compare conditions along the Souris River, which reached a historic crest

at Minot, North Dakota in June 2011. Land Floods Acquired May 11, 2011, and April 21, 2007,
these false-color images show the Mississippi River near Natchez, Mississippi. The image from
May 2011 shows flooded conditions. Land Floods September 6, 2020JPEGSeptember 7, 2023JPEGSeptember
6, 2020September 7, 2023September 6, 2020JPEGSeptember 7, 2023JPEGSeptember 7, 2023JPEGAfter
rapidly growing in volume just a few years earlier, northwest Iran’s Lake Urmia nearly dried

out in autumn 2023. The largest lake in the Middle East and one of the largest hypersaline
lakes on Earth at its greatest extent, Lake Urmia has for the most part transformed into a
vast, dry salt flat. On September 7, 2023, the OLI-2 (Operational Land Imager-2) on Landsat
9 captured this image (right) of the desiccated lakebed. It stands in contrast to the image
from three years earlier (left), acquired by the OLI on Landsat 8 on September 8, 2020, when

water filled most of the basin and salt deposits were only visible around the perimeter of
the lake. The replenishment followed a period of above-average precipitation that sent a surge
of freshwater into the basin, expanding its watery footprint. Drier conditions have since
brought levels back down. The longer-term trend for Urmia has been one toward drying. In 1995,
Lake Urmia reached a high-water mark; then in the ensuing two decades, the lake level dropped

more than 7 meters (23 feet) and lost approximately 90 percent of its area. Consecutive droughts,
agricultural water use, and dam construction on rivers feeding the lake have contributed to
the decline. A shrinking Lake Urmia has implications for ecological and human health. The
lake, its islands, and surrounding wetlands comprise valuable habitat and are recognized as
a UNESCO Biosphere Reserve, Ramsar site, and national park. The area provides breeding grounds

for waterbirds such as flamingos, white pelicans, and white-headed ducks, as well as a stopover
for migratory species. However, with low lake levels, what water remains becomes more saline
and taxes the populations of brine shrimp and other food sources for larger animals. A shrinking
lake also increases the likelihood of dust from the exposed lakebed becoming swept up by winds
and degrading air quality. Recent studies have linked the low water levels in Lake Urmia with

respiratory health impacts among the local population.The relative effects of climate, water
usage, and dams on Lake Urmia’s water level is a topic of debate. The lake did see some recovery
during a 10-year restoration program beginning in 2013. However, the efficacy of that effort
has been difficult to parse since strong rains also fell during that period. Some research
has concluded that climatic factors were primarily responsible for the recovery. NASA Earth

Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey.
Story by Lindsey Doermann.View this area in EO ExplorerA few years after a fresh influx of
water raised its levels, the large lake has nearly gone dry.Image of the Day for October 10,
2023 Image of the Day Land Water View more Images of the Day:Water levels are at their lowest
since 1937. Image of the Day Water Drought Fires Long and short. Deep and shallow. Salty and

fresh. Blue and brown. These are Africa’s Lake Tanganyika and Lake Rukwa. Image of the Day
Land Water In May 2016, the reservoir behind Hoover Dam reached its lowest level since the
1930s. Image of the Day Water When the water gets saltier in Iran’s largest lake, the microscopic
inhabitants can turn the water dark red. Image of the Day Water Water Color July 1 - September
30, 2023MPEG For several months in 2023, global sea surface temperatures reached record-high

levels, fueled by decades of human-caused climate warming and a recent boost from the natural
climate phenomenon El Niño. Some areas—including the seas around Florida, Cuba, and the Bahamas—saw
particularly high temperatures, with implications for the health of coral reefs.Corals thrive
within a small range of temperatures and become stressed when water is too hot or cold. Bleaching
occurs when stressed corals expel the algae that live inside them, stripping corals of their

color. Extreme bleaching can leave a reef susceptible to starvation, disease, and even death.
Observations made by divers in the Florida Keys found that the marine heatwave in summer 2023
caused widespread bleaching.Stress on corals can also be detected using data from satellites.
This animation shows the evolution of accumulated heat stress from July through September
2023. The colors depict “degree heating weeks” (°C-weeks)—a measure that provides an estimate

of the severity and duration of thermal stress. Data for the product are compiled by NOAA’s
Coral Reef Watch, which blends observations from polar orbiting satellites such as the NASA-NOAA
Suomi NPP, and from geostationary satellites such as GOES, with computer models.Observations
have shown that when the accumulated heat stress reaches a value of 4, significant coral bleaching
can result. At values of 8, coral bleaching and widespread mortality are likely. By midway

through this animation, in August, heat stress across much of the region already soared well
above both of those thresholds. According to NOAA, cumulative heat stress by late September
2023 hit 22°C-weeks (40°F-weeks), nearly triple the previous record for the region.Bleaching
was already observed in some areas as early as July. Notice that areas of coral reef (gray)
near the Florida Keys, Cuba, and the Bahamas, are among the first areas to show high cumulative

heat stress. Hurricane Idalia in late August helped cool surface waters somewhat, but only
temporarily.Nearing mid-October, waters around the Florida Keys were under a bleaching watch.
Further south, waters around parts of Cuba and the Bahamas remained at bleaching alert level
2, the highest level of the scale, signifying that severe bleaching and mortality are likely.NASA
Earth Observatory animation by Wanmei Liang, using Daily 5km Degree Heating Weeks data from

Coral Reef Watch. Coral reef data from UNEP-WCMC, WorldFish Centre, WRI, TNC. Story by Kathryn
Hansen.View this area in EO ExplorerThe seas around Florida, Cuba, and the Bahamas saw large
accumulations of heat stress beginning in summer 2023, with implications for the health of
coral reefs.Image of the Day for October 16, 2023 Image of the Day Water Temperature Extremes
View more Images of the Day:Warmer-than-average temperatures are showing up locally and globally,

with consequences for people, landscapes, and ecosystems. Image of the Day Water Image of
the Day Life Water Image of the Day Heat Life Water Studying corals from above could help
scientists understand how these critical ecosystems will weather a changing climate. Image
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Scientific Data volume 7, Article number: 112 (2020) Cite this article 30k Accesses126 Citations88
AltmetricMetrics detailsRemotely sensed biomass carbon density maps are widely used for myriad
scientific and policy applications, but all remain limited in scope. They often only represent

a single vegetation type and rarely account for carbon stocks in belowground biomass. To date,
no global product integrates these disparate estimates into an all-encompassing map at a scale
appropriate for many modelling or decision-making applications. We developed an approach for
harmonizing vegetation-specific maps of both above and belowground biomass into a single,
comprehensive representation of each. We overlaid input maps and allocated their estimates

in proportion to the relative spatial extent of each vegetation type using ancillary maps
of percent tree cover and landcover, and a rule-based decision schema. The resulting maps
consistently and seamlessly report biomass carbon density estimates across a wide range of
vegetation types in 2010 with quantified uncertainty. They do so for the globe at an unprecedented
300-meter spatial resolution and can be used to more holistically account for diverse vegetation

carbon stocks in global analyses and greenhouse gas inventories.Measurement(s)biomass carbon
densityTechnology Type(s)digital curationFactor Type(s)climatic zone • above or below ground
• land coverSample Characteristic - Environmentorganic materialSample Characteristic - LocationEarth
(planet)Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.11872383Terrestrial
ecosystems store vast quantities of carbon (C) in aboveground and belowground biomass1. At

any point in time, these stocks represent a dynamic balance between the C gains of growth
and C losses from death, decay and combustion. Maps of biomass are routinely used for benchmarking
biophysical models2,3,4, estimating C cycle effects of disturbance5,6,7, and assessing biogeographical
patterns and ecosystem services8,9,10,11. They are also critical for assessing climate change
drivers, impacts, and solutions, and factor prominently in policies like Reducing Emissions

from Deforestation and Forest Degradation (REDD+) and C offset schemes12,13,14. Numerous methods
have been used to map biomass C stocks but their derivatives often remain limited in either
scope or extent12,15. There thus remains a critical need for a globally harmonized, integrative
map that comprehensively reports biomass C across a wide range of vegetation types.Most existing
maps of aboveground biomass (AGB) and the carbon it contains (AGBC) are produced from statistical

or data-driven methods relating field-measured or field-estimated biomass densities and spaceborne
optical and/or radar imagery12,15,16. They largely focus on the AGB of trees, particularly
those in tropical landscapes where forests store the majority of the region’s biotic C in
aboveground plant matter. Land cover maps are often used to isolate forests from other landcover
types where the predictive model may not be appropriate such that forest AGB maps intentionally

omit AGB stocks in non-forest vegetation like shrublands, grasslands, and croplands, as well
as the AGB of trees located within the mapped extent of these excluded landcovers17. Non-forest
AGB has also been mapped to some extent using similar approaches but these maps are also routinely
masked to the geographic extent of their focal landcover18,19,20,21. To date, there has been
no rigorous attempt to harmonize and integrate these landcover-specific, remotely sensed products

into a single comprehensive and temporally consistent map of C in all living biomass.Maps
of belowground biomass (BGB) and carbon density (BGBC) are far less common than those of AGB
because BGB cannot be readily observed from space or airborne sensors. Consequently, BGB is
often inferred from taxa-, region-, and/or climate-specific “root-to-shoot” ratios that relate
the quantity of BGB to that of AGB22,23,24. These ratios can be used to map BGB by spatially

applying them to AGB estimates using maps of their respective strata5. In recent years, more
sophisticated regression-based methods have been developed to predict root-to-shoot ratios
of some landcover types based on covariance with other biophysical and/or ecological factors25,26.
When applied spatially, these methods can allow for more continuous estimates of local BGB5,27.
Like AGBC, though, few attempts have been made to comprehensively map BGBC for the globe.Despite

the myriad of emerging mapping methods and products, to date, the Intergovernmental Panel
on Climate Change (IPCC) Tier-1 maps by Ruesch and Gibbs28 remains the primary source of global
AGBC and BGBC estimates that transcend individual landcover types. These maps, which represents
the year 2000, were produced prior to the relatively recent explosion of satellite-based AGB
maps and they therefore rely on an alternative mapping technique called “stratify and multiply”15,

which assigns landcover-specific biomass estimates or “defaults” (often derived from field
measurements or literature reviews) to the corresponding classified grid cells of a chosen
landcover map12. While this approach yields a comprehensive wall-to-wall product, it can fail
to capture finer-scale spatial patterns often evident in the field and in many satellite-based
products12,15. The accuracy of these maps is also tightly coupled to the quality and availability

of field measurements29 and the thematic accuracy and discontinuity of the chosen landcover
map.Given the wealth of landcover-specific satellite based AGB maps, a new harmonization method
akin to “stratify and multiply” is needed to merge the validated spatial detail of landcover-specific
remotely sensed biomass maps into a single, globally harmonized product. We developed such
an approach by which we (i) overlay distinct satellite-based biomass maps and (ii) proportionately

allocate their estimates to each grid cell (“overlay and allocate”). Specifically, we overlay
continental-to-global scale remotely sensed maps of landcover-specific biomass C density and
then allocate fractional contributions of each to a given grid cell using additional maps
of percent tree cover, thematic landcover and a rule-based decision tree. We implement the
new approach here using temporally consistent maps of AGBC as well as matching derived maps

of BGBC to generate separate harmonized maps of AGBC and BGBC densities. In addition, we generate
associated uncertainty layers by propagating the prediction error of each input dataset. The
resulting global maps consistently represent biomass C and associated uncertainty across a
broad range of vegetation in the year 2010 at an unprecedented 300 meter (m) spatial resolution.Our
harmonization approach (Fig. 1) relies on independent, landcover-specific biomass maps and

ancillary layers, which we compiled from the published literature (Table 1). When published
maps did not represent our epoch of interest (i.e. grasslands and croplands) or did not completely
cover the necessary spatial extent (i.e. tundra vegetation), we used the predictive model
reported with the respective map to generate an updated version that met our spatial and temporal
requirements. We then used landcover specific root-to-shoot relationships to generate matching

BGBC maps for each of the input AGBC maps before implementing the harmonization procedure.
Below we describe, in detail, the methodologies used for mapping AGBC and BGBC of each landcover
type and the procedure used to integrate them.Generalized, three-step workflow used to create
harmonized global biomass maps. In step one, woody AGB maps are prepared, combined, converted
to AGBC density and used to create separate but complementary maps of BGBC. In step two, a

similar workflow is used to generate matching maps of AGBC and BGBC for tundra vegetation,
grasses, and annual crops. In step three, all maps are combined using a rule-based decision
tree detailed in Fig. 3 to generate comprehensive, harmonized global maps. All input data
sources are listed and described in Table 1.Since the first remotely sensed woody AGB maps
were published in the early 1990s, the number of available products has grown at an extraordinary

pace16 and it can thus be challenging to determine which product is best suited for a given
application. For our purposes, we relied on the GlobBiomass AGB density map30 as our primary
source of woody AGB estimates due to its precision, timestamp, spatial resolution, and error
quantification. It was produced using a combination of spaceborne optical and synthetic aperture
radar (SAR) imagery and represents the year 2010 at a 100 m spatial resolution – making it

the most contemporary global woody AGB currently available and the only such map available
for that year. Moreover, GlobBiomass aims to minimize prediction uncertainty to less than
30% and a recent study suggests that it has high fidelity for fine-scale applications31.The
GlobBiomass product was produced by first mapping the growing stock volume (GSV; i.e. stem
volume) of living trees, defined following Food and Agriculture Organization (FAO) guidelines32

as those having a diameter at breast height (DBH) greater than 10 centimeters (cm). AGB density
was then determined from GSV by applying spatialized biomass expansion factors (BEFs) and
wood density estimates. These factors were mapped using machine learning methods trained from
a suite of plant morphological databases that compile thousands of field measurements from
around the globe33. The resulting AGB estimates represent biomass in the living structures

(stems, branches, bark, twigs) of trees with a DBH greater than 10 cm. This definition may
thereby overlook AGB of smaller trees and/or shrubs common to many global regions. Unlike
other maps, though, the GlobBiomass product employs a subpixel masking procedure that retains
AGB estimates in 100 m grid cells in which any amount of tree cover was detected in finer
resolution (30 m) imagery34. This unique procedure retains AGB estimates in tree-sparse regions

like savannahs, grasslands, croplands, and agroforestry systems where AGB is often overlooked17,
as well as in forest plantations. The GlobBiomass product is the only global map that also
includes a dedicated uncertainty layer reporting the standard error of prediction. We used
this layer to propagate uncertainty when converting AGB to AGBC density, modelling BGBC, and
integrating with C density estimates of other vegetation types.Bouvet et al.35 – some of whom

were also participants of the GlobBiomass project – independently produced a separate AGB
density map for African savannahs, shrublands and dry woodlands circa 2010 at 25 m spatial
resolution35 (hereafter “Bouvet map”), which we included in our harmonized product to begin
to address the GlobBiomass map’s potential omission of small trees and shrubs that do not
meet the FAO definition of woody AGB. This continental map of Africa is based on a predictive

model that directly relates spaceborne L-band SAR imagery – an indirect measure of vegetation
structure that is sensitive to low biomass densities36 – with region-specific, field-measured
AGB. Field measurements (n = 144 sites) were compiled from 7 different sampling campaigns
– each specifically seeking training data for biomass remote sensing – that encompassed 8
different countries35. The resulting map is not constrained by the FAO tree definition and

is masked to exclude grid cells in which predicted AGB exceeds 85 megagrams dry mater per
hectare (Mg ha−1) – the threshold at which the SAR-biomass relationship saturates. To avoid
extraneous prediction, it further excludes areas identified as “broadleaved evergreen closed-to-open
forest”, “flooded forests”, “urban areas” and “water bodies” by the European Space Agency’s
Climate Change Initiative (CCI) Landcover 2010 map37 and as “bare areas” in the Global Land

Cover (GLC) 2000 map38. While the Bouvet map is not natively accompanied by an uncertainty
layer, its authors provided us with an analytic expression of its uncertainty (SE; standard
error of prediction) as a function of estimated AGB (Eq. 1) which we used to generate an uncertainty
layer for subsequent error propagation.We combined the GlobBiomass and Bouvet products to
generate a single woody biomass map by first upscaling each map separately to a matching 300

m spatial resolution using an area-weighted average to aggregate grid cells, and then assigning
the Bouvet estimate to all overlapping grid cells, except those identified by the CCI Landcover
2010 map as closed or flooded forest types (Online-only Table 1) which were not within the
dryland domain of the Bouvet map. While more complex harmonization procedures based on various
averaging techniques have been used by others39,40, their fidelity remains unclear since they

fail to explicitly identify and reconcile the underlying source of the inputs’ discrepancies41.
We thus opted to use a more transparent ruled-based approach when combining these two woody
biomass maps, which allows users to easily identify the source of a grid cell’s woody biomass
estimate. Given the local specificity of the training data used to produce the Bouvet map,
we chose to prioritize its predictions over those of the GlobBiomass product when within its

domain. In areas of overlap, the Bouvet map values tend to be lower in moist regions and higher
in dryer regions (Fig. 2), though, where used, these differences rarely exceed ±25 megagrams
C per hectare (MgC ha−1).Difference between underlying woody aboveground biomass maps in Africa.
Maps considered are the GlobBiomass30 global map and the Bouvet35 map of Africa. Both maps
were aggregated to a 300 m spatial resolution and converted to C density prior to comparison

using the same schema. The difference map was subsequently aggregated to a 3 km spatial resolution
and reprojected for visualization. Negative values denote lower estimates by Bouvet et al.35,
while positive values denote higher estimates.We then converted all woody AGB estimates to
AGBC by mapping climate and phylogeny-specific biomass C concentrations from Martin et al.42.
Climate zones were delineated by aggregating classes of the Köppen-Gieger classification43

(Table 2) to match those of Martin et al.42. Phylogenetic classes (angiosperm, gymnosperm
and mixed/ambiguous) were subsequently delineated within each of these zones using aggregated
classes of the CCI Landcover 2010 map (Online-only Table 1). Martin et al.42 only report values
for angiosperms and gymnosperms so grid cells with a mixed or ambiguous phylogeny were assigned
the average of the angiosperm and gymnosperm values and the standard error of this value was

calculated from their pooled variance. Due to residual classification error in the aggregated
phylogenetic classes, we weighted the phylogeny-specific C concentration within each climate
zone by the binary probability of correctly mapping that phylogeny (i.e. user’s accuracy)44
using Eq. 2where, within each climate zone, μc is the mean probability-weighted C concentration
of the most probable phylogeny, μm is the mean C concentration of that phylogeny from Martin

et al.42, pm is the user’s accuracy of that phylogeny’s classification (Table 3), and μn and
μo are the mean C concentrations of the remain phylogenetic classes from Martin et al.42.
Standard error estimates for these C concentrations were similarly weighted using summation
in quadrature (Eq. 3)where \({\sigma }_{c}\) is the probability-weighted standard error of
the most probable phylogeny’s C concentration and \({\sigma }_{m}\), \({\sigma }_{n}\) and

\({\sigma }_{o}\) are the standard errors of the respective phylogeny-specific C concentrations
from Martin et al.42. Probability-weighted C concentrations used are reported in Table 4.Mapped,
probability-weighted C estimates were then arithmetically applied to AGB estimates. Uncertainty
associated with this correction was propagated using summation in quadrature of the general
form (Eq. 4)where \({\mu }_{f}=f(i,j,\ldots ,k)\), \({\sigma }_{f}\) is the uncertainty of

μf, and \({\sigma }_{i},{\sigma }_{j},\ldots ,{\sigma }_{k}\), are the respective uncertainty
estimates of the dependent parameters (standard error unless otherwise noted). Here, μf, is
the estimated AGBC of a given grid cell, and is the product of its woody AGB estimate, and
its corresponding C concentration.The tundra and portions of the boreal biome are characterized
by sparse trees and dwarf woody shrubs as well as herbaceous cover that are not included in

the GlobBiomass definition of biomass. AGB density of these classes has been collectively
mapped by Berner et al.18,45 for the North Slope of Alaska from annual Landsat imagery composites
of the normalized difference vegetation index (NDVI) and a non-linear regression-based model
trained from field measurements of peak AGB that were collected from the published literature
(n = 28 sites). Berner et al.18 note that while these field measurements did not constitute

a random or systematic sample, they did encompass a broad range of tundra plant communities.
In the absence of a global map and due the sparsity of high quality Landsat imagery at high
latitudes, we extended this model to the pan-Arctic and circumboreal regions using NDVI composites
created from daily 250 m MODIS Aqua and Terra surface reflectance images46,47 that were cloud
masked and numerically calibrated to Landsat ETM reflectance – upon which the tundra model

is based – using globally derived conversion coefficients48. We generated six separate 80th
percentile NDVI composites circa 2010 – one for each of the MODIS missions (Aqua and Terra)
in 2009, 2010 and 2011 – following Berner et al.18. We chose to use three years of imagery
(circa 2010) rather than just one (2010) to account for the potential influence that cloud
masking may exert upon estimates of the 80th NDVI percentile in a single year. We then applied

the tundra AGB model to each composite, converted AGB estimates to AGBC by assuming a biomass
C fraction of 49.2% (SE = 0.8%)42 and generated error layers for each composite from the reported
errors of the AGB regression coefficients and the biomass C conversion factor using summation
in quadrature as generally described above (Eq. 4). A single composite of tundra AGBC circa
2010 was then created as the pixelwise mean of all six composites. We also generated a complementary

uncertainty layer representing the cumulative standard error of prediction, calculated as
the pixelwise root mean of the squared error images in accordance with summation in quadrature.
Both maps were upscaled from their native 250 m spatial resolution to a 300 m spatial resolution
using an area weighted aggregation procedure, whereby pixels of the 300 m biomass layer was
calculated as the area weighted average of contained 250 m grid cells, and the uncertainty

layer was calculated – using summation in quadrature – as the root area-weighted average of
the contained grid cells squared.Grassland AGBC density was modelled directly from maximum
annual NDVI composites using a non-linear regression-based model developed by Xia et al.19
for mapping at the global scale. This model was trained by relating maximum annual NDVI as
measured by the spaceborne Advanced Very High-Resolution Radiometer (AVHRR) sensor to globally

distributed field measurements of grassland AGBC that were compiled from the published literature
(81 sites for a total of 158 site-years). Like the tundra biomass training data, these samples
did not constitute a random or systematic sample but do encompass a comprehensive range of
global grassland communities. Given the inevitable co-occurrence of trees in the AVHRR sensor’s
8 km resolution pixels upon which the model is trained, it’s predictions of grassland AGBC

are relatively insensitive to the effects of co-occurring tree cover. We thereby assume that
its predictions for grid cells containing partial tree cover represent the expected herbaceous
AGBC density in the absence of those trees. Maximum model predicted AGBC (NDVI = 1) is 2.3
MgC ha−1 which is comparable to the upper quartile of herbaceous AGBC estimates from global
grasslands49 and suggests that our assumption will not lead to an exaggerated estimation.

For partially wooded grid cells, we used modelled grassland AGBC density to represent that
associated with the herbaceous fraction of the grid cell in a manner similar to Zomer et al.17
as described below (See “Harmonizing Biomass Carbon Maps”).We applied the grassland AGBC model
to all grid cells of maximum annual NDVI composites produced from finer resolution 16-day
(250 m) MODIS NDVI imagery composites circa 201050,51. Here again, three years of imagery

were used to account for potential idiosyncrasies in a single year’s NDVI composites resulting
from annual data availability and quality. As with AGB of tundra vegetation, annual composites
(2009–2011) were constructed separately from cloud-masked imagery collected by both MODIS
missions (Aqua and Terra; n = 6) and then numerically calibrated to AVHRR reflectance using
globally derived conversion coefficients specific to areas of herbaceous cover52. We then

applied the AGBC model to each of these composites and estimated error for each composite
from both the AVHRR calibration (standard deviation approximated from the 95% confidence interval
of the calibration scalar) and the AGBC model (relative RMSE) using summation in quadrature.
A single map of grassland AGBC circa 2010 was then created as the pixelwise mean of all six
composites and an associated error layer was created as the pixelwise root mean of the squared

error images. Both maps were aggregated from their original 250 m resolution to 300 m to facilitate
harmonization using the area-weighted procedure described previously for woody and tundra
vegetation (see section 1.2).Prior to harvest, cropland biomass can also represent a sizable
terrestrial C stock. In annually harvested cropping systems, the maximum standing biomass
of these crops can be inferred from annual net primary productivity (ANPP). While spaceborne

ANPP products exist, they generally perform poorly in croplands53,54. Instead, cropland ANPP
is more commonly derived from crop yields20,21,53. We used globally gridded, crop-specific
yields of 70 annually harvested herbaceous commodity crops circa 2000 by Monfreda et al.20
– the only year in which these data were available. These maps were produced by spatially
disaggregating crop-yield statistics for thousands of globally distributed administrative

units throughout the full extent of a satellite-based cropland map20. These maps were combined
with crop-specific parameters (Online-only Table 2) to globally map AGBC as aboveground ANPP
for each crop following the method of Wolf et al.21. This method can be simplified as (Eq.
5)where y is the crop’s yield (Mg ha−1), ω is the dry matter fraction of its harvested biomass,
h is its harvest index (fraction of total AGB collected at harvest) and c is the carbon content

fraction of its harvested dry mass. This simplification assumes, following Wolf et al.21,
that 2.5% of all harvested biomass is lost between the field and farmgate and that unharvested
residue and root mass is 44% C.Total cropland AGBC density was then calculated as the harvested-area-weighted
average of all crop-specific AGBC estimates within a given grid cell. Since multiple harvests
in a single year can confound inference of maximum AGBC from ANPP, we further determined the

harvest frequency (f) of each grid cell by dividing a cell’s total harvested area (sum of
the harvested area of each crop reported within a given grid cell) by its absolute cropland
extent as reported in a complementary map by Ramankutty et al.55. If f was greater than one,
multiple harvests were assumed to have occurred and AGBC was divided by f to ensure that AGBC
estimates did not exceed the maximum standing biomass density.Since the yields of many crops

and, by association, their biomass have changed considerably since 200056,57, we calibrated
our circa 2000 AGBC estimates to the year 2010 using local rates of annual ANPP change (MgC
ha−1 yr−1) derived as the Theil-Sen slope estimator – a non-parametric estimator that is relatively
insensitive to outliers – of the full MODIS Terra ANPP timeseries (2000–2015)58. Total ANPP
change between 2000 and 2010 for each grid cell was calculated as ten times this annual rate

of change. Since MODIS ANPP represents C gains in both AGB and BGB, we proportionately allocated
aboveground ANPP to AGBC using the total root-to-shoot ratio derived from the circa 2000 total
crop AGBC and BGBC maps (described below). Since error estimates were not available for the
yield maps or the crop-specific parameters used to generate the circa 2000 AGBC map, estimated
error of the circa 2010 crop AGBC map was exclusively based on that of the 2000–2010 correction.

The error of this correction was calculated as the pixel-wise standard deviation of bootstrapped
simulations (n = 1000) in which a random subset of years was omitted from the slope estimator
in each iteration. The 8 km resolution circa 2000 AGBC map and error layer were resampled
to 1 km to match the resolution of MODIS ANPP using the bilinear method prior to ANPP correction
and then further resampled to 300 m to facilitate harmonization.Woody crops like fruit, nut,

and palm oil plantations were not captured using the procedure just described and their biomass
was instead assumed to be captured by the previously described woody biomass products which
retained biomass estimates in all pixels where any amount of tree cover was detected at the
sub-pixel level (see section 1.1).Matching maps of BGBC and associated uncertainty were subsequently
produced for each of the landcover-specific AGBC maps using published empirical relationships.With

the exception of savannah and shrubland areas, woody BGBC was modelled from AGBC using a multiple
regression model by Reich et al.25 that considers the phylogeny, mean annual temperature (MAT),
and regenerative origin of each wooded grid cell and that was applied spatially using maps
of each covariate in a fashion similar to other studies5,27. Tree phylogeny (angiosperm or
gymnosperm) was determined from aggregated classes of the CCI Landcover 2010 map37 (Online-only

Table 1) with phylogenetically mixed or ambiguous classes assumed to be composed of 50% of
each. MAT was taken from version 2 of the WorldClim bioclimatic variables dataset (1970–2000)
at 1 km resolution59 and resampled to 300 m using the bilinear method. Since there is not
a single global data product mapping forest management, we determined tree origin – whether
naturally propagated or planted – by combining multiple data sources. These data included

(i) a global map of “Intact Forest Landscapes” (IFL) in the year 201360 (a conservative proxy
of primary, naturally regenerating forests defined as large contiguous areas with minimal
human impact), (ii) a Spatial Database of Planted Trees (SDPT) with partial global coverage61,
(iii) national statistics reported by the FAO Global Forest Resources Assessment (FRA) on
the extent of both naturally regenerating and planted forests and woodlands within each country

in the year 201062, and (iv) national statistics reported by the FAOSTAT database (http://www.fao.org/faostat)
on the planted area of plantation crops in 2010. Within each country, we assumed that the
total area of natural and planted trees was equal to the corresponding FRA estimates. If the
FAOSTAT-reported area of tree crops exceeded FRA-reported planted area, the difference was
added to FRA planted total. All areas mapped as IFL were assumed to be of natural origin and

BGB was modelled as such. Likewise, besides the exceptions noted below, all tree plantations
mapped by the SDPT were assumed to be of planted origin. In countries where the extent of
the IFL or SDPT maps fell short of the FRA/FAOSTAT reported areas of natural or planted forests,
respectively, we estimated BGBC in the remaining, unknown-origin forest grid cells of that
country (BGBCu), as the probability-weighted average of the planted and natural origin estimates

using Eq. 6where \(BGB{C}_{p}\) and \(BGB{C}_{n}\) are the respective BGBC estimates for a
grid cell assuming entirely planted and natural origin, respectively, and \({\Delta }_{p}\)
and \({\Delta }_{n}\) are the respective differences between (i) the FRA/FAOSTAT and (ii)
mapped extent of planted and natural forest within the given grid cell’s country. While the
mapped extent of IFL forests within a given country never exceeded that country’s FRA reported

natural forest extent, there were infrequent cases (n = 22 of 257) in which the mapped extent
of tree plantations exceeded the corresponding FRA/FAOSTAT estimate of planted forest area.
In these cases, we down-weighted the BGB estimates of SDPT forests in a similar fashion such
that the weight of their planted estimate (\({\omega }_{p}\)) was equal to the quotient of
(i) the FRA/FAOSTAT planted area and (ii) the SDPT extent within the country, and the weight

of the natural origin estimate applied to the SDPT extent (\({\omega }_{n}\)) was equal to
\(1-{\omega }_{p}\).A BGBC error layer was then produced using summation in quadrature from
the standard error estimates of the model coefficients, the AGBC error layer, the relative
RMSE of MAT (27%), and the derived global uncertainty of the phylogeny layer. Phylogeny error
was calculated as the Bernoulli standard deviation (δ) of the binary probability (p) of correct

classification (i.e. “area weighted user’s accuracy”44; Table 3) using Eq. 7.Since savannahs
and shrublands are underrepresented in the regression-based model25, their BGBC was instead
estimated using static root-to-shoot ratios reported by Mokany et al.22, which are somewhat
conservative in comparison to the IPCC Tier-1 defaults23,24 put favoured for consistency with
methods used for grasslands (see below). Error was subsequently mapped from that of the AGBC

estimates and the root-to-shoot ratios applied (Table 5).BGBC of tundra vegetation was mapped
from AGBC using a univariate regression model derived by Wang et al.26 that predicts root-to-shoot
ratio as a function of MAT. We applied the model using the WorldClim version 2 MAT map59 and
propagated error from the AGBC estimates, the relative RMSE of MAT and the standard error
of regression coefficients. Where tundra AGB exceeded 25 Mg ha−1 – the maximum field-measured

shrub biomass reported by Berner et al.18 – vegetation was considered to include trees and
the Reich et al.25 method described earlier for woody vegetation was used instead.In the absence
of a continuous predictor of grassland root-to-shoot ratios, we applied climate specific root-to-shoot
ratios from Mokany et al.22 to the corresponding climate regions of the Köppen-Gieger classification43
(Table 2). Here, again, these ratios vary slightly from the IPCC Tier-1 defaults23,24 but

were chosen for their greater sample size and specificity. Grassland BGBC error was mapped
from the error of the AGBC estimates and the respective root-to-shoot ratios.Cropland BGBC
was again estimated from crop-specific yields and morphological parameters (Online-only Table
2) following Wolf et al.21 and Eq. 8where y is the crop’s yield (Mg ha−1), r is the root-to-shoot
ratio of the crop, and h is its harvest index. Here again we assume that 2.5% of all harvested

biomass is lost between the field and farmgate and that root biomass is 44% C, following Wolf
et al.21. BGBC error was mapped from the error of the 2000-to-2010 ANPP correction for BGBC
allocation as described above for cropland AGBC.The AGBC and BGBC maps were harmonized separately
following the same general schema (Fig. 3). Given that our harmonized woody biomass map contains
biomass estimates for grid cells in which any amount of tree cover was detected at the subpixel

level (see section 1.1), we conserved its estimates regardless of the landcover reported by
the 2010 CCI map in order to more fully account for woody biomass in non-forested areas17.
We then used the MODIS continuous vegetation fields percent tree cover map for 201063 to allocate
additional biomass density associated with the most probable herbaceous cover (grass or crop)
to each grid cell in quantities complementary to that of the grid cell’s fractional tree cover

estimate (Eq. 9)where μT is the total biomass estimate of a grid cell, μw is the woody biomass
estimate for the grid cell, μh is its herbaceous biomass estimate, and q is the MODIS fractional
tree cover of the grid cell. Since MODIS tree cover estimates saturate at around 80%64, we
linearly stretched values such that 80% was treated as complete tree cover (100%). Moreover,
we acknowledge that percent cover can realistically exceed 100% when understory cover is considered

but we were unable to reasonably determine the extent of underlying cover from satellite imagery.
As such, our approach may underestimate the contribution of herbaceous C stocks in densely
forested grid cells. The most likely herbaceous cover type was determined from the CCI Landcover
2010 map, which we aggregated into two “likely herbaceous cover” classes – grass or crop –
based on the assumed likelihood of cropland in each CCI class (Online-only Table 1). However,

due to inherent classification error in the native CCI Landcover map, when determining the
herbaceous biomass contribution we weighted the relative allocation of crop and grass biomass
to a given grid cell based on the probability of correct classification by the CCI map (i.e.
“user’s accuracy”, Table 6) of the most probable herbaceous class (\({p}_{i}\)) such that
μh can be further expressed as (Eq. 10)where μi is the predicted biomass of the most probable

herbaceous class, and μj is that of the less probable class.Decision tree used to allocate
landcover-specific biomass estimates to each grid cell of our harmonized global products.The
uncertainty of a grid cell’s total AGBC or BGBC estimate (\({\sigma }_{T}\)) was determined
and mapped from that of its components (\({\mu }_{w}\,{\rm{and}}\,{\mu }_{h}\)) by summation
in quadrature which can be simplified as (Eq. 11)where \({\sigma }_{w}\) is the error of the

grid cell’s estimated μw, \({\sigma }_{h}\) is the error of its estimated μh, and \({\sigma
}_{q}\) is the error of its q. Here, \({\sigma }_{h}\) can be further decomposed and expressed
as Eq. 12 to account for the accuracy weighted allocation procedure expressed previously (Eq.
10)where \({\sigma }_{i}\) is the error of the estimated biomass density of the most probable
herbaceous class, \({\delta }_{i}\) is the estimated standard deviation of that class’s Bernoulli

probability (p; Eq. 7), and \({\sigma }_{j}\) is the error of the estimated biomass density
of the less probable herbaceous subclass.Exceptions to the above schema were made in the tundra
and boreal biomes – as delineated by the RESOLVE Ecoregions 2017 biome polygons65 – where
thematic overlap was likely between the woody and tundra plant biomass maps. A separate set
of decision rules (Fig. 3) was used to determine whether grid cells in these biomes were to

be exclusively allocated the estimate of the tundra plant map or that of the fractional allocation
procedure described above. In general, any land in these biomes identified as sparse landcover
by the CCI landcover map (Online-only Table 1) was assigned the tundra vegetation estimate.
In addition, lands north of 60° latitude with less than 10% tree cover or where the tundra
AGBC estimate exceeded that of the woody AGBC estimate were also exclusively assigned the

tundra vegetation estimate. Lands north of 60° latitude not meeting these criteria were assigned
the woody value with the additional contribution of grass.Subtle numerical artefacts emerged
from the divergent methodologies employed north and south of 60°N latitude. These were eliminated
by distance weighting grid cells within 1° of 60°N based on their linear proximity to 60°N
and then averaging estimates such that values at or north of 61°N were exclusively based on

the northern methodology, those at 60°N were the arithmetic average of the two methodologies
and those at or south of 59°N were exclusively based on the southern methodology. This produced
a seamless, globally harmonized product that integrates the best remotely sensed estimates
of landcover-specific C density. Water bodies identified as class “210” of the CCI 2010 landcover
map were then masked from our final products.Data layers (n = 4, Table 7) for the maps of

AGBC and BGBC density (Fig. 4) as well as their associated uncertainty maps which represent
the combined standard error of prediction (Fig. 5) are available as individual 16-bit integer
rasters in GeoTiff format. All layers are natively in a WGS84 Mercator projection with a spatial
resolution of approximately 300 m at the equator and match that of the ESA CCI Landcover Maps37.
Raster values are in units megagrams C per hectare (MgC ha−1) and have been scaled by a factor

of ten to reduce file size. These data are accessible through the Oak Ridge National Laboratory
(ORNL) DAAC data repository (https://doi.org/10.3334/ORNLDAAC/1763)66. In addition, updated
and/or derived vegetation-specific layers that were used to create our harmonized 2010 maps
are available as supplemental data on figshare67.Globally harmonized maps of above and belowground
living biomass carbon densities. (a) Aboveground biomass carbon density (AGBC) and (b) belowground

biomass carbon density (BGBC) are shown separately. Maps have been aggregated to a 5 km spatial
resolution and reprojected here for visualization.Uncertainty of grid cell level above and
belowground biomass carbon density estimates. Uncertainty is shown here as the coefficient
of variation (%; standard error layer divided by mean estimate layer) of estimated AGBC (a)
and BGBC (b) densities after harmonization. Maps have been aggregated to a 5 km spatial resolution

and projected for visualization.Our harmonized products rely almost exclusively upon maps
and models that have been rigorously validated by their original producers and were often
accompanied by constrained uncertainty estimates. Throughout our harmonization procedure,
we strived to conserve the validity of each of these products by minimizing the introduction
of additional error and by tracking any introductions, as described above, such that the final

error layers represent the cumulative uncertainty of the inputs used. Ground truth AGB and
BGB data are almost always collected for individual landcover types. Consequently, we are
unable to directly assess the validity of our integrated estimates beyond their relationships
to individual landcover-specific estimates and the extents to which they were modified from
their original, previously-validated form prior to and during our harmonization procedure.Temporal

and spatial updates made to existing landcover-specific maps of non-tree AGB resulted in relatively
small changes to their predictions. For example, we used numerically calibrated MODIS imagery
to extend the Landsat-based tundra plant AGB model beyond its native extent (the North Slope
of Alaska) to the pan-Arctic region since neither a comparable model nor a consistent Landsat
time series were available for this extent. We assessed the effects of these assumptions by

comparing our predictions for the North Slope with those of the original map18 (Fig. 6a).
Both positive and negative discrepancies exist between ours and the original, though these
rarely exceed ±2 MgC ha−1 and no discernibly systematic bias was evident.Differences between
landcover-specific AGBC estimates from the original published maps and the modified versions
used as inputs to create the 2010 harmonized global maps. Tundra vegetation AGBC (a) is compared

to the Landsat-based map of Berner et al.45 for the north slope of Alaska after converting
it to units MgC ha−1. Here, the comparison map was subsequently aggregated to a 1 km resolution
and reprojected for visualization. Grassland AGBC (b) is compared to the AVHRR-based map of
Xia et al.19 which represents the average estimate between 1982–2006. For visualization, the
map was aggregated to a 5 km resolution and subsequently reprojected after being masked to

MODIS IGBP grasslands in the year 200685 following Xia et al.19. As such, this map does not
necessarily represent the spatial distribution of grid cells in which grassland estimates
were used. Cropland AGBC (c) is compared to the original circa 2000 estimates to assess the
effects of the 2000-to-2010 correction. The map is masked to the native extent of the combined
yield maps and aggregated to a 5 km resolution for visualization. For all maps, negative values

indicate that our circa 2010 estimates are lower than those of the earlier maps while positive
values indicate higher estimates.Our updated map of grassland biomass carbon in the year 2010
was similarly made by applying the original AVHRR-based model to calibrated MODIS imagery.
This too resulted in only subtle changes to the original biomass map (Fig. 6b) that were rarely
in excess of 0.5 MgC ha−1. In most areas, our estimates were higher than those of Xia et al.19

who mapped the mean AGBC density between 1986 and 2006. Most of these elevated estimates corresponded
with areas in which significant NDVI increases (“greening”) have been reported while notably
lower estimates in the Argentine Monte and Patagonian steppe biomes of southern South America,
likewise, correspond with areas of reported “browning”68,69. Both greening and browning trends
are well documented phenomena and have been linked to climatic changes70. Moreover, we further

compared AGBC estimates from both the original Xia et al.19 map and our 2010 update to AGBC
field measurements coordinated by the Nutrient Network that were collected from 48 sites around
the world between 2007 and 200949. The RMSE (0.68 MgC ha−1) of our updated map was 10% less
that of the Xia et al. map for sites with less than 40% tree cover. Likewise, our 2010 estimates
were virtually unbiased (bias = −0.01 MgC ha−1) in comparison to the Xia map (bias = 0.25

MgC ha−1). While still noisy, these results suggest that our temporal update improved the
overall accuracy of estimated grassland AGBC.Finally, cropland biomass carbon maps were also
updated from their native epoch (2000) to 2010 using pixel-wise rates of MODIS ANPP change
over a ten-year period. While MODIS ANPP may be a poor snapshot of crop biomass in a single
year, we assumed that its relative change over time reflects real physiological shifts affecting

the cropland C cycle. This correction also resulted in only small differences that rarely
exceeded ±2 MgC ha−1 and that, spatially, correspond well with observed declines in the yields
of select crops that have been linked to climate change71,72 (Fig. 6c). Nonetheless, updated
global yield maps comparable to those available for 2000 would greatly improve our understanding
of the interactions between climate change, crop yields, and C dynamics.Belowground biomass

is notoriously difficult to measure, model, and also to validate. We accounted for the reported
uncertainty of nearly every variable considered when estimating belowground biomass and pixel-level
uncertainty, but we were unable to perform an independent validation of our harmonized estimates
at the pixel level due to a paucity of globally consistent field data. To complete such a
task, a globally orchestrated effort to collect more BGB samples data across all vegetation

types is needed.Given this lack of data, we instead compared the estimated uncertainty of
our BGBC maps to that of our AGBC estimates to infer the sources of any divergence (Fig. 5).
As expected, our cumulative BGBC uncertainty layer generally reveals greater overall uncertainty
than our AGBC estimates, with BGBC uncertainty roughly twice that of AGBC throughout most
of the globe. The highest absolute uncertainty was found in biomass rich forests. Arid woodlands,

especially those of the Sahel and eastern Namibia, generally had the greatest relative BGBC
uncertainty, though their absolute uncertainty was quite small (generally less than 3 MgC
ha−1). Here, biomass estimates of sparse woody vegetation were primarily responsible for heightened
relative uncertainty. High relative and absolute BGBC uncertainty were also associated with
predictions in select mountainous forests (e.g. east central Chile) as well as forested areas

in and around cities. These patterns were largely driven by AGB uncertainty in the GlobBiomass
product.The GlobBiomass global woody AGB map produced by Santoro et al.30 comprises the backbone
of our integrated products and, with few exceptions, remains largely unchanged in our final
AGBC map. The native version of the GlobBiomass map is accompanied by an error layer describing
the uncertainty of each pixel’s biomass estimate and this too forms the core of our integrated

uncertainty layers. In areas with tree cover, the global average error of GlobBiomass estimates
is 39 Mg ha−1 or 50% with greater relative uncertainty in densely forested areas, along the
margins of forested expanses like farm fields and cities, and in similar areas with sparse
tree cover.Adding additional grass or crop biomass in complementary proportion to a grid cell’s
tree cover often did not exceed the estimated error of the original GlobBiomass map (Fig.

7). Grid cells exceeding GlobBiomass’s native uncertainty comprise less than 40% of its total
extent. Exceptions were primarily found in grassland and cropland dominated regions where
tree cover was generally sparse, and, consequently, the herbaceous biomass contribution was
relatively high. Even so, the absolute magnitude of these additions remains somewhat small
(less than 2.3 MgC ha−1 for grassland and 15 MgC ha−1 for cropland).Differences between the

final harmonized AGBC map and GlobBiomass AGBC. GlobBiomass AGB was aggregated to a 300 m
spatial resolution and converted to C density prior to comparison. Negative values indicate
areas where the new map reports lower values than GlobBiomass while positive value denote
higher estimates.Larger deviations from GlobBiomass were also present in areas of both dryland
Africa and the Arctic tundra biome, where we used independent layers to estimate woody biomass.

In African drylands, GlobBiomass likely underestimates woody biomass by adopting the conservative
FAO definition (DBH > 10 cm), which implicitly omits the relatively small trees and shrubs
that are common to the region. The Bouvet map of Africa that we used to supplement these estimates
is not bound by this constraint, was developed from region-specific data, and predicts substantially
higher AGB density throughout much of its extent with comparatively high accuracy (RMSE =

17.1 Mg ha−1)35.GlobBiomass also included sporadic biomass estimates throughout much of the
Arctic tundra biome. Trees are generally scarce throughout this biome, which is instead dominated
by dwarf shrubs and herbaceous forbs and graminoids, so given GlobBiomass’s adherence to FAO
guidelines, its predictions here may be spurious. We thus prioritized the estimates of the
independent model developed specifically to collectively predict biomass of both woody and

herbaceous tundra vegetation. These estimates were generally higher than GlobBiomass but agreed
well with independent validation data from North America (RMSE = 2.9 Mg ha−1)18.While far
from a perfect comparison, the only other map to comprehensively report global biomass carbon
density for all landcover types is the IPCC Tier-1 map for the year 2000 by Ruesch and Gibbs28.
As previously described, this map was produced using an entirely different method (“stratify

and multiply”) and distinct data sources23 and represents an earlier epoch. However, the map
is widely used for myriad applications, and it may thus be informative to assess notable differences
between it and our new products.Ruesch and Gibbs28 report total living C stocks of 345 petagrams
(PgC) in AGBC and 133 PgC in BGBC for a total of 478 PgC, globally. Our estimates are lower
at 287 PgC and 122 PgC in global AGBC and BGBC, respectively, for a total of 409 PgC in living

global vegetation biomass. Herbaceous biomass in our maps comprised 9.1 and 28.3 PgC of total
AGBC and BGBC, respectively. Half of all herbaceous AGBC (4.5 PgC) and roughly 6% of all herbaceous
BGBC (1.7 PgC) was found in croplands. Moreover, we mapped 22.3 and 6.1 PgC, respectively,
in the AGB and BGB of trees located within the cropland extent. These trees constituted roughly
7% of all global biomass C and are likely overlooked by both the Ruesch and Gibbs map28 and

by remotely sensed forest C maps that are masked to forested areas. Zomer et al.17 first highlighted
this potential discrepancy in the Ruesch and Gibbs map28 when they produced a remarkably similar
estimate of 34.2 Pg of overlooked C in cropland trees using Tier-1 defaults. However, their
estimates were assumed to be in addition to the 474 PgC originally mapped by Ruesch and Gibbs28.
Here, we suggest that the 28.4 PgC we mapped in cropland trees is already factored into our

409 PgC total.Our AGBC product predicts substantially less biomass C than Ruesch and Gibbs28
throughout most of the pantropical region and, to a lesser extent, southern temperate forests
(Fig. 8a). This pattern has been noted by others comparing the Ruesch and Gibbs map28 to other
satellite-based biomass maps73 and may suggest that the IPCC default values used to create
it23 are spatially biased. In addition, well-defined areas of high disagreement emerge in

Africa that directly correspond with the FAO boundaries of the “tropical moist deciduous forest”
ecofloristic zone and suggest that this area, in particular, may merit critical review. Moreover,
the opposite pattern is observed in this same ecofloristic zone throughout South America.
Our map also predicts greater AGBC throughout much of the boreal forest as well as in African
shrublands and the steppes of South America.Differences between the 2010 harmonized global

maps of above and belowground biomass carbon density and those of the IPCC Tier-1 product
by Ruesch and Gibbs for 2000. Comparisons of AGBC (a) and BGBC (b) maps are shown separately.
Negative values indicate that the circa 2010 estimates are comparatively lower while positive
values indicate higher estimates.We observed similar, though less pronounced discrepancies,
when comparing BGBC maps (Fig. 8b). Notably, our map predicts substantially more BGBC throughout

the tundra biome – a previously underappreciated C stock that has recently risen to prominance74
– the boreal forest, African shrublands and most of South America and Australia. However,
we predict less BGBC in nearly all rainforests (Temperate and Tropical). These differences
and their distinct spatial patterns correspond with the vegetation strata used to make the
IPCC Tier-1 map28 and suggest that the accuracy of the “stratify and multiply” method depends

heavily upon the quality of the referenced and spatial data considered. Inaccuracies in these
data may, in turn, lead to false geographies. Integrating, continuous spatial estimates that
better capture local and regional variation, as we have done, may thus greatly improve our
understanding of global carbon geographies and their role in the earth system.The error and
variance between our woody biomass estimates – when aggregated to the country level – and

comparable totals reported in the FRA were less for comparisons made against FRA estimates
generated using higher tier IPCC methodologies than for those based on Tier-1 approaches (Fig.
9). Across the board for AGBC, BGBC, and total C comparisons, the relative RMSE (RMSECV) of
our estimates, when compared to estimates generated using high tier methods, was roughly half
of that obtained from comparisons with Tier-1 estimates (Table 8). Likewise, the coefficient

of determination (R2) was greatest for comparisons with Tier-3 estimates. For each pool-specific
comparison (AGBC, BGBC, and total C), the slopes of the relationships between Tier-1, 2, and
3 estimates were neither significantly different from a 1:1 relationship nor from one another
(p > 0.05; ANCOVA). Combined, these results suggest that our maps lead to C stock estimates
congruent with those attained from independent, higher-tier reporting methodologies.Comparison

of woody biomass density estimates to corresponding estimates of the FAO’s FRA and the USFS’s
FIA. National woody AGBC totals derived from the woody components of our harmonized maps are
compared to national totals reported in the 2015 FRA62 (a) in relation to the IPCC inventory
methodology used by each country. Likewise, we derived woody AGBC totals for US states and
compared them to the corresponding totals reported by the 2014 FIA75 (b), a Tier-3 inventory.

We also show the additional effect of considering non-woody C – as is reported in our harmonized
maps – in light green. Similar comparisons were made between our woody BGBC estimates and
the corresponding estimates of both the FRA (c) and FIA (d). We further summed our woody AGBC
and BGBC estimates and compared them to the total woody C stocks reported by both the FRA
(e) and FIA (f).To explore this association at a finer regional scale, we also compared our

woody C estimates to the United States Forest Service’s Forest Inventory Analysis75 (FIA)
and found similarly strong congruence for AGBC and Total C stocks but subtle overestimates
for BGBC (Fig. 9). The FIA is a Tier-3 inventory of woody forest biomass C stocks that is
based on extensive and statistically rigorous field sampling and subsequent upscaling, We
used data available at the state level for the year 2014 – again, the only year in which we

could obtain data partitioned by AGBC and BGBC. Like our FRA comparison, we found a tight
relationship between our woody AGBC totals and those reported by the FIA (Fig. 9b; RMSECV
= 25.7%, R2 = 0.960, slope = 1.10, n = 48). Our woody BGBC estimates, though, were systematically
greater than those reported by the FIA (Fig. 9d; RMSECV = 86.4%, R2 = 0.95, slope = 1.51,
n = 48). This trend has been noted by others27 and suggests that the global model that we

used to estimate woody BGBC may not be appropriate for some finer scale applications as is
foretold by the elevated uncertainty reported in our corresponding uncertainty layer (Fig.
5b). Our total woody C (AGBC + BGBC) estimates (Fig. 9f), however, agreed well with the FIA
(RMSECV = 34.1%, R2 = 0.961, slope = 1.17, n = 48) and thus reflect the outsized contribution
of AGBC to the total woody C stock. When the contribution of herbaceous C stocks is further

added to these comparisons, our stock estimates intuitively increase in rough proportion to
a state’s proportional extent of herbaceous cover. The effect of this addition is particularly
pronounced for BGBC estimates due to the large root-to-shoot ratios of grassland vegetation.The
relative congruence of our results with higher-tier stock estimates suggests that our maps
could be used to facilitate broader adoption of higher-tier methods among countries currently

lacking the requisite data and those seeking to better account for C in non-woody biomass.
This congruence spans a comprehensive range of biophysical conditions and spatial scales ranging
from small states to large nations. Moreover, a recent study suggests that the fidelity of
the underlying GlobBiomass AGB map may extend to even finer scales31. While our BGBC estimates
may differ from some fine-scale estimates (Fig. 9d), their tight agreement with high tier

BGBC totals at the national level (Fig. 9c) suggests that they may still be well suited for
many national-scale C inventories – especially for countries lacking requisite high tier data.
Use of our maps is unlikely to introduce error in excess of that currently implicit in Tier-1
estimates. Credence, though, should be given to the associated uncertainty estimates. To facilitate
wider adoption of higher-tier methodologies, our maps could be used to derive new, region-specific

default values for use in Tier-2 frameworks76 or to either represent or calibrate 2010 baseline
conditions in Tier-3 frameworks. In so doing, inventories and studies alike could more accurately
account for the nuanced global geographies of biomass C.These maps are intended for global
applications in which continuous spatial estimates of live AGBC and/or BGBC density are needed
that span a broad range of vegetation types and/or require estimates circa 2010. They are

loosely based upon and share the spatial resolution of the ESA CCI Landcover 2010 map37, which
can be used to extract landcover specific C totals. However, our products notably do not account
for C stored in non-living C pools like litter or coarse woody debris, nor soil organic matter,
though these both represent large, additional ecosystem C stocks77,78,79. Our maps are explicitly
intended for global scale applications seeking to consider C in the collective living biomass

of multiple vegetation types. For global scale applications focused exclusively on the C stocks
of a single vegetation type, we strongly encourage users to instead use the respective input
map or model referenced in Table 1 to avoid potential errors that may have been introduced
by our harmonization procedure. For AGB applications over smaller extents, users should further
consider whether locally specific products are available. If such maps are not available and

our maps are considered instead, credence should be given to their pixel-level uncertainty
estimates. As mentioned above, the biomass of shrublands was only explicitly accounted for
in Africa and the Arctic tundra, since neither broad-scale maps nor models generalizable to
other areas were available in the existing literature. As such, we caution against the use
of our maps outside of these areas when shrubland biomass is of particular interest or importance.

Moreover, in contrast to the estimates for all other vegetation types considered, which we
upscaled to a 300 m resolution, cropland C estimates were largely based on relatively coarse
8 km resolution data that were downscaled using bilinear resampling to achieve a 300 m spatial
resolution. As such, these estimates may not adequately capture the underlying finer-scale
spatial variation and should be interpreted with that in mind. Likewise, we reiterate that

some BGBC estimates may differ from locally derived Tier-3 estimates, and attention should
thus be given to our reported pixel-level uncertainty for all applications. Finally, our maps
should not be used in comparison with the IPCC Tier-1 map of Ruesch and Gibbs (2008) to detect
biomass change between the two study periods due to significant methodological differences
between these products.Cropland biomass maps were created in the R statistical computing environment80.

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Institute of Food and Agricultural Sciences, 2002).Download referencesWe gratefully acknowledge
all the data producers, without whom this work would not be possible. We especially thank
Maurizio Santoro et al., Alexandre Bouvet et al., Jiangzhou Xia et al., Logan T. Berner et
al., Chad Monfreda et al., and Julie Wolf et al. whose AGB estimates comprise the core of

our harmonized products and, in many cases, whose feedback greatly improved the quality of
their inclusion. We are also grateful to the thoughtful feedback of three anonymous reviewers
whose suggestions greatly improved the quality of our products and the clarity of our manuscript.
Funding for this project was generously provided by the David and Lucile Packard Foundation
and the National Wildlife Federation.Department of Geography, University of Wisconsin-Madison,

Madison, WI, USASeth A. Spawn, Clare C. Sullivan & Holly K. GibbsCenter for Sustainability
and the Global Environment (SAGE), Nelson Institute for Environmental Studies, University
of Wisconsin-Madison, Madison, WI, USASeth A. Spawn, Clare C. Sullivan, Tyler J. Lark & Holly
K. GibbsYou can also search for this author in PubMed Google ScholarYou can also search for
this author in PubMed Google ScholarYou can also search for this author in PubMed Google ScholarYou

can also search for this author in PubMed Google ScholarS.A.S. designed the harmonization
procedure, compiled and standardized individual biomass layers, conducted all mapping, and
led manuscript development. C.C.S., T.J.L. and H.K.G. assisted with conceptualization, and
manuscript development.Correspondence to Seth A. Spawn.The authors declare no competing interests.Publisher’s
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with this article.Reprints and PermissionsSpawn, S.A., Sullivan, C.C., Lark, T.J. et al. Harmonized
global maps of above and belowground biomass carbon density in the year 2010. Sci Data 7,
112 (2020). https://doi.org/10.1038/s41597-020-0444-4Download citationReceived: 03 July 2019Accepted:
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these processes can be analyzed from ground, air, or space-based measurements.The Sun influences
a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on
the land surface and underground in the form of lakes, rivers, and groundwater along with

total water storage.Whether you are a scientist, an educator, a student, or are just interested
in learning more about NASA’s Earth science data and how to use them, we have the resources
to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making
NASA's free and open Earth science data interactive, interoperable, and accessible for research

and societal benefit both today and tomorrow.Changes in the land surface can impact climate,
terrestrial ecosystems, and hydrology. Land surface-related data, including land cover type,
land surface temperature, and topography, are critical for monitoring agricultural practices
and water resource availability and for guiding interventions when necessary.Land surface
reflectance is a measure of the fraction of incoming solar radiation reflected from Earth's

surface to a satellite-borne or aircraft-borne sensor. These data are useful because they
provide an estimate of the surface spectral reflectance as it would be measured at ground
level in the absence of atmospheric scattering or absorption, which is referred to as atmospheric
correction.Land surface reflectance data can be used for visualizing the surface as well as
for computing metrics and creating models that are useful for specific analysis. Agricultural

production estimates must be restricted to crop-specific areas (e.g., corn, soybeans, etc.)
to avoid confusion with other crops, natural vegetation, and areas of no vegetation. This
allows specific crops to be observed over time using sustained land imaging and multi-spectral
high-resolution imagery.An asterisk (*) next to an entry indicating that near real-time (NRT)
data products are available through NASA's Land, Atmosphere Near real-time Capability for

EOS (LANCE) within three hours from satellite observation. Imagery is generally available
3-5 hours after observation. While not intended for scientific research, NRT data are good
resources for monitoring ongoing or time-critical events.Sensor(s)/ Model NameObservation
or Model500 m, 1 km, 5,600 m2017-present15 m, 30 m, 60 mOLI/OLI-2: 9 bands ranging from 0.43
µm to 1.38 µmETM+: 8 bands ranging from 0.45 µm to 12.5 µmTM: 7 bands ranging in wavelength

from 0.45 µm to 2.35 µmOLI-2, OLI, ETM+, TMGeoTIFFOLI/OLI-2: 9 bands ranging from 0.43 µm
to 1.38 µmMSI: 12 bands ranging from 0.443 µm to 2.190 µmThe Advanced Spaceborne Thermal Emission
and Reflection Radiometer (ASTER) instrument is a cooperative effort between NASA and Japan's
Ministry of Economy, Trade and Industry (METI). ASTER Surface Reflectance data can be visualized
and interactively explored using NASA Worldview:Research quality ASTER data products are available

through Earthdata Search:Back to the TableThe Enhanced Thematic Mapper (ETM+), the Operational
Land Imager (OLI) and OLI-2, and the Thermal Infrared Sensor-2 (TIRS-2) are aboard the joint
NASA/USGS Landsat series of satellites.OLI data can be visualized and interactively explored
using NASA Worldview:Research quality Landsat land surface reflectance data products can be
accessed directly using USGS EarthExplorer:Back to the TableHarmonized Landsat Sentinel-2

(HLS) data provide consistent global observation of Earth’s surface reflectance and top-of-atmosphere
(TOA) brightness data from the Landsat OLI and OLI-2 and the ESA (European Space Agency) Multi-Spectral
Instrument (MSI) aboard the Sentinel-1A/B satellites every 2-3 days with 30 meter spatial
resolution.HLS Surface Reflectance data can be visualized and interactively explored using
NASA Worldview:Research quality HLS data products can be accessed directly from Earthdata

Search:The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) tool
offers a simple and efficient way to access, transform, and visualize geospatial data from
a variety of federal data archives, including USGS Landsat Analysis Ready Data (ARD) surface
reflectance products. Back to the TableModerate Resolution Imaging Spectroradiometer (MODIS)
Surface Reflectance products provide an estimate of the surface spectral reflectance as it

would be measured at ground level in the absence of atmospheric scattering or absorption.MODIS
Surface Reflectance data can be visualized and interactively explored using NASA Worldview:Multiple
Geographic Information Systems (GIS) MODIS Surface Reflectance data layers with different
band combinations are available through Esri’s ArcGIS OnLine (AGOL). NASA GIS data may be
used with open-source GIS software such as Quantum GIS or Geographic Resources Analysis Support

System (GRASS). Learn more about these tools in the Use the Data section below.Research quality
MODIS data products can be accessed directly from Earthdata Search:Near real-time (NRT) MODIS
Surface Reflectance data are available through NASA’s Land, Atmosphere Near real-time Capability
for EOS (LANCE) within 60 to 125 minutes after a satellite observation:Back to the TableThe
Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is aboard the NASA/NOAA Suomi

National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 satellites. VIIRS/NPP Land Surface
Reflectance Data from Earthdata Search Data are available daily and 8-day at various spatial
resolutions.Near real-time (NRT) VIIRS Surface Reflectance data are available through LANCE
within 60 to 125 minutes after a satellite observation:Back to the TableLand Surface Temperature
(LST) describes processes such as the exchange of energy and water between the land surface

and Earth's atmosphere. LST influences the rate and timing of plant growth and is affected
by the albedo, or reflectance, of a surface. These data can improve decision-making for water
use and irrigation strategies, and are also an indicator for crop health and water stress.An
asterisk (*) next to an entry indicating that near real-time (NRT) data products are available
through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) within three hours

from satellite observation. Imagery is generally available 3-5 hours after observation. While
not intended for scientific research, NRT data are good resources for monitoring ongoing or
time-critical events.1 km, 0.05°0.25°, 0.5°, 1° GeoTIFFMODIS LST data can be visualized and
interactively explored using NASA Worldview:MODIS LST data can be visualized in Giovanni:Research
quality LST data products can be accessed directly from Earthdata Search and also are available

through the Data Pool at NASA’s Land Processes DAAC (LP DAAC).The AppEEARS tool and MODIS
subsetting tools can be used to quickly extract a subset of MODIS data for a region of interest.Near
real-time (NRT) MODIS LST data are available through LANCE within 60 to 125 minutes after
a satellite observation.Back to the TableResearch quality LST data from the Advanced Spaceborne
Thermal Emission and Reflection Radiometer (ASTER) are available in HDF-EOS format:Back to

the TableA suite of MODIS LST and Emissivity (LST&E) products are available that combine MODIS
data with ASTER data to leverage the strengths from both sensors. These integrated LST data
can be visualized and interactively explored using NASA Worldview:Back to the TableThe ECOsystem
Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission measures the
temperature of plants to better understand how much water plants need and how they respond

to stress.The AppEEARS tool and MODIS subsetting tools can be used to quickly extract a subset
of ECOSTRESS data for a region of interest.Back to the TableThe Visible Infrared Imaging Radiometer
Suite (VIIRS) instrument is aboard the NASA/NOAA Suomi National Polar-orbiting Partnership
(Suomi NPP) and NOAA-20 satellites. Research quality LST data products from VIIRS: Near real-time
(NRT) VIRS LST data are available through LANCE within 60 to 125 minutes after a satellite

observation:Back to the TableLST data are produced as part of the NASA/USGS Landsat series
of Earth observing missions.<LST data through the USGS EarthExplorerBack to the TableThe NASA
Making Earth System Data Records for Use in Research Environments (MEaSUREs) provides Land
Surface Temperature (LST) derived from the Low Earth Orbit (LEO) satellite data record from
the Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer

Suite (VIIRS) instruments as well as LST error estimates for both day and night.Back to the
TableNASA’s Land Data Assimilation System (LDAS) uses sophisticated numerical models of physical
processes to integrate multiple satellite and ground-based data products. LDAS uses advanced
land surface modeling and assimilation techniques to deliver physically consistent and spatially
and temporally continuous data.LDAS and its various projects have a variety of uses:LDAS components

and projects:LDAS LST data can be visualized in Giovanni. Monthly data are available from
2002:Research quality NLDAS LST data products: Please see the LDAS FAQ for additional ways
to obtain, subset, and view LDAS datasets, including fast time series "data rods", file format
conversion, and other web services that provide LDAS data.Back to the TableModern-Era Retrospective
analysis for Research and Applications version 2 (MERRA-2) is the latest version of global

atmospheric satellite data reanalysis produced by NASA’s Global Modeling and Assimilation
Office (GMAO). The dataset covers 1980-present with the latency of approximately three weeks
after the end of a month.NRT imagery of LST data can be interactively explored using NASA
Worldview:MERRA-2 data can be visualized in Giovanni. Monthly data are available starting
in 2002:MERRA-2 LST data are available for download in Earthdata Search.Back to the TableThe

NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) dataset is comprised of
high-resolution, bias-corrected global downscaled climate projections derived from the General
Circulation Model (GCM) runs conducted under the Coupled Model Intercomparison Project Phase
6 (CMIP6) and across all four “Tier 1” greenhouse gas emissions scenarios known as Shared
Socioeconomic Pathways (SSPs). This dataset provides a set of global, high resolution, bias-corrected

climate change projections that can be used to evaluate climate change impacts on processes
that are sensitive to finer-scale climate gradients and the effects of local topography on
climate conditions. Uses include: air temperature, precipitation volume, humidity, stellar
radiation, and atmospheric wind speed.NEX-GDDP-CMIP6 data are available through the NASA Center
for Climate Simulation (NCCS):Back to the TableAn understanding of topography is essential

when assessing an area's runoff potential, the availability of water in lower-lying areas,
a site’s suitability for planting, and other site-specific applications. These data are often
in the form of Digital Elevation Models (DEMs) or grids with values representing the height
of a cell.Sensor(s)/ Model NameHDF-EOS or GeoTIFF51.6° N and 51.6° SOne of the most common
topography data sources is the Shuttle Radar Topography Mission (SRTM). SRTM provides a DEM

of all land between 60° north and 56° south latitude, which encompasses about 80% of Earth's
landmass. The Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
Digital Elevation Model provides a global digital elevation model (DEM) of land areas on Earth
at a spatial resolution of 1 arc second (approximately 30 meter horizontal posting at the
equator).DEM data accuracy is typically very sensitive to vegetation cover; however, data

from the ASTER instrument tend to perform better over specific landcover types. Applications
include identifying crop stress, mapping surface temperatures of soils and geology, and measuring
surface heat balance.The NASADEM data product was released in February 2020 and provides 1
arc-second resolution. NASADEM extends the legacy of the SRTM by improving the DEM height
accuracy and data coverage as well as providing additional SRTM radar-related data products.Imagery

can be interactively explored using NASA Worldview:Research quality topography data products
are available from Earthdata Search:In addition to Earthdata Search, SRTM and ASTER data can
be accessed through AppEEARS.Back to the TableThe Global Ecosystem Dynamics Investigation
(GEDI) Level 3 Land Surface Metrics dataset provides gridded mean canopy height, standard
deviation of canopy height, mean ground elevation, standard deviation of ground elevation,

and counts of laser footprints per 1 km x 1 km grid cells within 52° north and south latitude.
Data are available from April 2019 through 2022. Level 3 gridded products can be used to create
digital elevation models, characterize important carbon and water cycling processes, and more.
Users may download customized subsets (Level 3 and Level 4) of GEDI data using the Spatial
Data Access Tool through the at The Oak Ridge National Laboratory Distributed Active Archive

Center (ORNL DAAC).GEDI L3 Gridded Land Surface Metrics data can be visualized and interactively
explored using NASA Worldview:Research quality data can be accessed using Earthdata Search:Back
to the TableVegetation is a key component of the overall Earth system. It plays a critical
role in the movement of water at all levels, including the ecosystem and landscape levels.
Assessments of vegetation health, including vegetation greenness, land cover type, evapotranspiration,

and evaporative stress, are critical to monitoring agricultural practices and water resource
availability and for deciding when interventions are necessary.Aboveground Biomass (AGB) is
a widely-used variable that helps characterize the growth of crops and forecast their yields.The
Global Ecosystem Dynamics Investigation (GEDI) is a joint mission between NASA and the University
of Maryland, with the instrument installed on the International Space Station. Data acquired

using the instrument’s three lasers are used to construct detailed 3D maps of forest canopy
height and the distribution of branches and leaves. GEDI data play an important role in understanding
the amounts of biomass and carbon forests store and how much they lose when disturbed. GEDI
data also can be used to study plant and animal habitats and biodiversity along with how these
change over time. New research supported by NASA Harvest reveals these data also can be used

to map where different types of crops are being grown.Research quality Level 3 data can be
accessed using Earthdata Search:GEDI Level 4B data provide gridded 1km x 1km estimates of
mean aboveground biomass density (AGBD). This dataset provides gridded estimates of aboveground
biomass density at a greater accuracy and resolution than previously available.Model GEDI
AGBD data can be accessed using Earthdata Search:The Evaporative Stress Index (ESI) describes

temporal anomalies in ET and highlights areas with anomalously high or low rates of water
use across the land surface. ESI also demonstrates the capability for capturing early signals
of "flash drought" brought on by extended periods of hot, dry, and windy conditions that can
lead to rapid soil moisture depletion.30 m, 70 mTarget areas every 1-7 daysThe Ecostress ESI
product is derived from the ratio of Level 3 actual ET to potential ET (PET). ESI data can

be used to assess agricultural drought and observe vegetation stress.Water use efficiency
(WUE) is the ratio of carbon stored by plants to water evaporated by plants. This ratio is
given as grams of carbon stored per kilogram of water evaporated over the course of the day
from sunrise to sunset on the day when the ECOSTRESS data granule is acquired.Level 4 (modeled)
ECOSTRESS ESI and WUE products can be accessed using Earthdata Search:MODIS ESI data can be

visualized in a web map service via ArcGIS REST Service:Evapotranspiration (ET) is the sum
of evaporation from the land surface and transpiration in vegetation. ET measurements are
useful in monitoring and assessing water availability, drought conditions, and crop production.
An increase in available energy through changes in cloud cover, seasonal lengthening of daylight,
and similar variables favors primary production and ET. This, in turn, extracts available

water from the soil and represents the largest component of consumptive water use in the U.S.
If this soil water is not replenished through rain or irrigation, plants close their stomata
to retain water and primary production is reduced. By comparing observed ET to a modeled expectation
of crop water requirements, ET observations can be used to schedule irrigation applications
and improve agricultural water management.ET can't be measured directly with satellite instruments

because it is modeled based on variables including land surface temperature, air temperature,
and solar radiation. NASA has Level 4 data products that incorporate daily meteorological
reanalysis data with remote sensing data that provide estimations of ET, such as the MODIS
MOD16 product.30 m, 70 mNASA's ECOsystem Spaceborne Thermal Radiometer Experiment on Space
Station (ECOSTRESS), installed on the International Space Station in June 2018, measures the

temperature of plants to better understand how they respond to the stress of insufficient
water availability. Learn more in this YouTube video: Monitoring Plant Health from Space:
NASA’s ECOSTRESS Mission.Research quality ECOSTRESS ET data products can be accessed directly
using Earthdata Search or the Data Pool at LP DAAC. Datasets are available in HDF format but,
in some cases, customizable to GeoTIFF:MODIS aboard NASA's Terra and Aqua satellites yields

data that are used to estimate global terrestrial evapotranspiration using the MOD16 global
evapotranspiration product.Back to the TableThe Landsat Provisional Actual Evapotranspiration
(ETa) product can be used to better understand the spatiotemporal dynamics of water use over
land surfaces. Provisional ETa science products are available globally for Thematic Mapper
(TM), Enhanced Thematic Mapper Plus (ETM+), and Operational Land Imager/Thermal Infrared Sensor

(OLI/TIRS) scenes that can be successfully processed to Landsat Collection 2 Level-2 Surface
Temperature products.The Landsat 7 and 8 satellites orbit Earth every eight days. Each satellite
carries a thermal sensor that can measure the temperature of everything they pass over. The
sensor swath is 115 miles (185 kilometers) and the data in these images are provided at a
resolution of about a quarter of an acre, or roughly about the size of a baseball infield.

By combining these temperature measurements with other satellite and weather data, scientists
can calculate how much evapotranspiration is taking place. This provides an orbital view of
how much water is being used across the landscape and allows information to be provided for
individual fields and farms just about once a week.Research quality land surface reflectance
data products can be accessed directly using Earthdata Search:Back to the TableResearch quality

MODIS Level 4 ET products are available in yearly and 8-day temporal resolutions with 500
m pixel size:NASA's Land Data Assimilation System (LDAS) provides model-based ET data and
includes a global collection (GLDAS) and a North American collection (NLDAS). LDAS uses measurements
of precipitation, soil texture, topography, and leaf area index (LAI) to model soil moisture
and ET. When calculating ET, there are biases around seasonality or local-specific effects,

but the model developers try to account for these and calibrate accordingly. Estimates of
ET are provided every day and integrated to get monthly, seasonal, or annual information.GLDAS
data products can be visualized using a NASA interactive data analysis tool called Giovanni:Research
quality ET data are available through NASA’s Goddard Earth Sciences Data and Information Services
Center (GES DISC):Land cover data help quantify land degradation caused by deforestation for

agriculture and livestock production. NASA data are used, with other data, as tools for sustainable
land management strategies to maintain vegetative cover and health. 2001-2021The Moderate
Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Land Cover Type data product (MCD12Q1)
provides global land cover types at yearly intervals. This product is derived using supervised
classifications of MODIS surface reflectance data. The supervised classifications then undergo

additional post-processing that incorporates prior knowledge and ancillary information to
further refine specific land type classes.These data can be accessed and downloaded using
NASA Worldview and Earthdata Search:The Global Food Security-support Analysis Data 30 meter
(GFSAD30) collection from NASA NASA MEaSUREs provides global cropland extent data that are
divided and distributed into seven separate regional datasets for the year 2015 (2010 for

North America) at 30 m resolution. These datasets provide baseline data that are used in many
agricultural cropland studies pertaining to water sustainability and food security. Another
relevant dataset is the Global Hyperspectral Imaging Spectral-library of Agricultural crops
(GHISA). These data are available for the conterminous U.S. (GHISACONUS), and provide dominant
crop data (rice, corn, soybeans, cotton, and winter wheat) based on hyperspectral data from

the Hyperion instrument aboard NASA's Earth Observing-1 satellite (EO-1). Crop growth states
for major agricultural crops are included in the spectral library. GHISACASIA provides dominant
crop data (wheat, rice, corn, alfalfa, and cotton) in different growth stages across the Galaba
and Kuva farm fields in the Syr Darya river basin in Central Asia.GSFAD30 and GHISA data are
available through Earthdata Search:GSFAD and GHISA data also are available through NASA’s

LP DAAC:The USDA's interactive CropScape tool provides crop-specific land cover data layers
created annually for the continental U.S. using moderate resolution Landsat satellite imagery
and extensive agricultural validation from ground-based measurements. The USDA Crop Explorer
provides global information by region or by crop commodity. This service offers advanced tools
such as interactive visualization, web-based data dissemination and geospatial queries, and

automated data delivery to systems such as Google Earth.NASA’s Making Earth System Data Records
for Use in Research Environments (MEaSUREs) Global Land Cover Mapping and Estimation (GLanCE)
annual 30m Version 1 data product provides global land cover and land cover change data derived
from Landsat TM, ETM+, and OLI data. These maps provide the user community with land cover
type, land cover change, metrics characterizing the magnitude and seasonality of greenness

of each pixel, and the magnitude of change. This dataset is useful for a wide range of applications,
including ecosystem, climate, and hydrologic modeling; monitoring the response of terrestrial
ecosystems to climate change; carbon accounting; and land management. Leaf Area Index (LAI)
is a ratio of leaf surface area to ground surface area. This assigns a quantifiable value
to the amount of vegetation on the ground and is an important indicator of the condition and

future potential yield of a crop. Knowing the total leaf area in a plant canopy helps scientists
determine how much water will be stored and released by an ecosystem, how much leaf litter
it will generate, and how much photosynthesis is occurring. These data are used to estimate
crop characteristics and extrapolated to predict crop condition and future yield. The Multi-angle
Imaging SpectroRadiometer (MISR) Level 3 FIRSTLOOK Global Land product in netCDF format features

LAI. This data product is a global summary of the Level 2 land/surface parameters of interest
averaged over a month and reported on a geographic grid.Global MISR LAI data are available
to browse, visualize, and download through the MISR Level 3 Data Browser.Research quality
data are available through Earthdata SearchMODIS LAI data can be visualized and interactively
explored using NASA Worldview:MODIS LAI Level 4 data are available starting in 2000 through

Earthdata Search:VIIRS LAI Level 4 data are available starting in 2012 through Earthdata Search:LAI
data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter
plots, or a time series through Giovanni:MERRA-2 data are available for download in Earthdata
Search:Surface reflectance is a measure of the fraction of incoming solar radiation reflected
from Earth's surface to a satellite-borne or aircraft-borne sensor. It is useful for measuring

the greenness of vegetation, which can then be used to determine phenological transition dates
including the start of the growing season, the period of peak growth, and the end of the growing
season. Agricultural production estimates must be restricted to crop-specific areas to avoid
confusion with other crops, natural vegetation, and areas of no vegetation. This allows specific
crops to be followed through time using sustained land imaging and multi-spectral high-resolution

imagery.500 m, 1 km, 5,600 mOLI, OLI-2, MSIModerate Resolution Imaging Spectroradiometer (MODIS)
Surface Reflectance products provide an estimate of the surface spectral reflectance as it
would be measured at ground level in the absence of atmospheric scattering or absorption.MODIS
Surface Reflectance data can be visualized and interactively explored using NASA Worldview:Multiple
Geographic Information Systems (GIS) MODIS Surface Reflectance data layers with different

band combinations are available through Esri’s ArcGIS OnLine (AGOL). NASA’s GIS data may be
used with open source GIS software such as Quantum GIS or Geographic Resources Analysis Support
System (GRASS) GIS at no cost:Research quality MODIS data products can be accessed directly
from Earthdata SearchNear real-time (NRT) MODIS Surface Reflectance data are available through
NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) within 60 to 125 minutes

after a satellite observation:The Enhanced Thematic Mapper (ETM+) and the Operational Land
Imager (OLI) aboard the NASA/USGS Landsat 7 (ETM+) spacecraft and Landsat 8 (OLI) spacecraft
acquire VNIR data at 30 m spatial resolution every 16 days (fewer days as you move away from
the equator). Landsat 9 carries two instruments: the OLI-2 (which is a copy of the Landsat
8 OLI) and the Thermal Infrared Sensor-2 (TIRS-2). TIRS-2 measures land surface temperature

in two thermal infrared bands.Research quality surface reflectance data products can be accessed
using USGS EarthExplorer:Back to the TableA high-resolution land surface reflectance imagery
option is Harmonized Landsat Sentinel-2 (HLS). HLS imagery provide consistent surface reflectance
and top of atmosphere brightness data from the Landsat 8 OLI, the Landsat 9 OLI-2, and the
Multi-Spectral Instrument (MSI) aboard the ESA (European Space Agency) Sentinel-2A and Sentinel-2B

satellites. The harmonized measurement enables global land observations every 2-3 days at
30 m spatial resolution.Back to the TableThe Advanced Spaceborne Thermal Emission and Reflection
Radiometer (ASTER) instrument acquires visible and near-infrared (VNIR) reflectance data at
15 m spatial resolution and short wave infrared (SWIR) reflectance data at 30m spatial resolution.
ASTER data can be accessed and downloaded using NASA Worldview:ASTER is a cooperative effort

between NASA and Japan's Ministry of Economy Trade and Industry (METI). As a tasked sensor,
ASTER acquires data when it is directed to do so over specific targets. This makes its temporal
resolution variable depending on the requested target region of interest:Back to the TableThe
Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is aboard the NASA/NOAA Suomi
National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 satellites. VIIRS Surface Reflectance

data can be visualized and interactively explored using NASA Worldview: • VIIRS Surface Reflectance
data Research quality VIIRS data products can be accessed directly from Earthdata Search:
• VIIRS/NPP Land Surface Reflectance Data from Earthdata Search Data are available daily and
8-day at various spatial resolutions.Near real-time (NRT) VIIRS Surface Reflectance data are
available through LANCE within 60 to 125 minutes after a satellite observation:VIIRS/NPP Atmospherically

Corrected Surface Reflectance 6-Min L2 Swath IP 375m, 750m NRTVIIRS/NPP Surface Reflectance
Daily L2G Global 1km and 500m SIN Grid NRTVegetation indices can be used to measure the amount
of green vegetation over a given area, which is used as an assessment of vegetation health.
Commonly used vegetation indices are the Normalized Difference Vegetation Index (NDVI), Enhanced
Vegetation Index (EVI), and EVI2.The NDVI takes the difference between near-infrared (NIR)

and red reflectance divided by their sum: NDVI = (NIR - VIS)/(NIR + VIS). Resulting values
range from -1 to 1. Low values of NDVI correspond to low photosynthetic activity (e.g., unhealthy
vegetation) or non-vegetated surfaces, such as areas of rock, sand, exposed soils, or snow.
Higher NDVI values generally indicate greener, more lush vegetation, including forests, croplands,
and wetlands. The EVI minimizes canopy-soil variations and improves sensitivity over dense

vegetation. The EVI2 minimizes atmospheric effects.250 m, 500 m, 1 km500 m, 1 km, 0.05°0.5°
x 0.625°1980-presentVegetation products created from data acquired by the Moderate Resolution
Imaging Spectroradiometer (MODIS) instrument and the Visible Infrared Imaging Radiometer Suite
(VIIRS) can be accessed in several ways. Imagery can be interactively explored using NASA
Worldview:Note: The Terra/MODIS NDVI (rolling 8-day) and EVI (rolling 8-day) are only available

in Worldview for the last 20 days; older NDVI or EVI imagery are available using use the Level
3, 16-Day, or Monthly Vegetation Index and EVI layers.NDVI data products can be visualized
as a time-averaged map, an animation, seasonally-averaged maps, scatter plots, or a time series
using a NASA online interactive data analysis tool called Giovanni:Multiple Geographic Information
Systems (GIS) MODIS Surface Reflectance data layers with different band combinations are available

through Esri’s ArcGIS OnLine (AGOL). NASA GIS data may be used with open-source GIS software
such as Quantum GIS or Geographic Resources Analysis Support System (GRASS) GIS at no cost:Research
quality vegetation indices can be accessed directly using Earthdata Search (datasets are available
as in HDF format but are, in some cases, customizable to GeoTIFF):NRT MODIS vegetation data
can be accessed and downloaded through LANCE.MODIS NDVI Anomaly data are available through

the original Global Inventory Modeling and Mapping Studies (GIMMS) Global Agriculture Monitoring
System (GLAM) created by the University of Maryland with NASA and the USDA. The Global Agriculture
Monitoring system 2 (GLAM 2) was developed by NASA Harvest: NASA’s Food Security and Agriculture
Program. GLAM 2 is a near real-time monitoring of global croplands that enables users to track
crop conditions as growing seasons unfold. GLAM 2 offers NDVI along with a suite of meteorological

and soil moisture data. Since GLAM data processing is cloud-based and does not rely on local
bandwidth to compile datasets, users can access the publicly available web interface from
anywhere in the world. New functions, such as custom time series charts, cropland, and crop
type masks, have recently been implemented. Back to the TableBack to the TableWater is a key
component of the overall Earth system, cycling through each component, moving within the atmosphere,

the ocean, the cryosphere (including snow cover and snowpack), surface water of rivers and
lakes, and subsurface water. Water availability is critical for human consumption, agriculture
and food security, industry, and energy development. Assessing water availability, including
the amount and type of precipitation is critical to monitoring agricultural practices and
water resource availability and for providing interventions when necessary.According to the

U.N., water use has been growing globally at twice the rate as the global population is increasing.
More and more areas are reaching the limit at which water services can be sustainably delivered,
especially in arid regions. Groundwater, a major water resource for maintaining cropland productivity,
is declining through the extensive use of water for agricultural irrigation, where aquifer
recharge cannot keep up with groundwater extraction. Unfortunately, changes in terrestrial

water storage, especially with regard to groundwater, are poorly known and sparsely sampled.
Complicating matters further, global freshwater is not only unevenly distributed, but sources
of freshwater such as lakes and rivers often cross geopolitical boundaries. Integrating satellite
data with land-based and other measurements, geospatial data, and hydrologic models help to
better understand controls on global water resources and how changing water resources impact

social-environmental systems across geopolitical boundaries.380 km2Instruments aboard the
joint NASA/German Space Agency Gravity Recovery And Climate Experiment (GRACE, operational
2002 to 2017) and GRACE Follow-On (GRACE-FO, launched in 2018) satellites obtain measurements
about changes in Earth's gravity. Since water has mass, changes in groundwater storage can
be detected as changes in gravity. GRACE and GRACE-FO measurements help assess water storage

changes in monthly, total surface, and groundwater depth. These data are available from 2002
to present; the data track total water storage time-variations and anomalies (changes from
the time-mean) at a resolution of approximately 90,000 km2 and larger. These measurements
are unimpeded by clouds and track the entire land water column from the surface down to deep
aquifers. GRACE and GRACE-FO data are uniquely valuable for regional studies to determine

general trends in land water storage as well as for assessing basin-scale water budgets (e.g.,
the balance between precipitation, evapotranspiration, and runoff).The GRACE and GRACE-FO
Mascon Ocean, Ice, and Hydrology Equivalent Water Height dataset provides gridded monthly
global water storage/height anomalies relative to a time-mean. The data are processed at NASA’s
Jet Propulsion Laboratory (JPL) using the mascon approach. Mass Concentration blocks (mascons)

are a form of gravity field basis functions to which GRACE observations are optimally fit.
For more information on this approach, see the JPL Monthly Mass Grids webpage. Data are represented
as Water Equivalent Thickness (WET), representing the total terrestrial water storage anomalies
from soil moisture, snow, surface water (including rivers, lakes, and reservoirs), as well
as groundwater and aquifers.GRACE and GRACE-FO data can be visualized and interactively explored

using tools below. Both products incorporate a Coastal Resolution Improvement filter that
reduces leakage errors across coastlines:Research-quality data products can be accessed using
Earthdata Search:Scientists at NASA's Goddard Space Flight Center use GRACE-FO data to generate
weekly groundwater and soil moisture drought indicators. The drought indicators describe current
wet or dry conditions, expressed as a percentile showing the probability of occurrence for

a specific location and time of year, with lower values (orange/red) indicating drier than
normal conditions and higher values (blues) indicating wetter than normal conditions. The
drought model is also used to make forecasts of expected drought conditions one, two, and
three months into the future.Back to the TableGRACE Groundwater storage percentile modeled
data:Back to the TableWeekly groundwater and soil moisture drought indicators are available

each week based on terrestrial water storage observations derived from GRACE satellite data
and integrated with other observations using a sophisticated numerical model of land surface
water and energy processes:Back to the TableNASA, in collaboration with other agencies, has
developed models of groundwater that incorporate satellite information with ground-based data
(when ground-based data are available). These models are part of the Land Data Assimilation

System (LDAS), which includes a global collection (GLDAS) and a North American collection
(NLDAS). GLDAS Groundwater Storage data have spatial resolution of 0.25° and are available
at daily temporal resolution. GLDAS data are available from January 1948 to present:NASA's
Goddard Earth Sciences Data and Information Services Center (GES DISC) optimally reorganized
some large hydrological datasets as time series (also known as data rods) for a set of water

cycle-related variables from the NLDAS and GLDAS, the Land Parameter Parameter Model (LPRM),
TRMM, and GRACE data assimilation. These are available at GES DISC Hydrology Data Rods. Back
to the TableThe Modern-Era Retrospective analysis for Research and Applications, Version 2
(MERRA-2) provides data beginning in 1980. Due to the amount of historical data available,
MERRA-2 data can be used to look for trends and patterns, as well as anomalies. There are

several options available: hourly and monthly from 1980.MERRA-2 Groundwater model data:Back
to the TableSurface runoff is the volume of available surface water after a precipitation
event that has been partitioned into evapotranspiration (ET) and stored as soil moisture.
This available water may be used for irrigation, domestic use, and for livestock. Droughts
are indicated by lower surface runoff anomaly values showing that water reservoirs have received

less than normal amounts of surface runoff. Elevated total runoff anomaly values may indicate
flooding events and have lasting impacts on crops, livestock, and residents. Runoff potential
is important data for water resources and agricultural management, especially after storm
events and wildfires. Runoff can impact water quality as chemicals from fertilizers and stormwater
runoff, debris, and waste products enter water bodies. Satellites cannot measure runoff directly;

however, information that can be used to predict runoff can be measured remotely. These data
are then input, along with ground-based data, into land surface models to estimate runoff.
NASA's Land Data Assimilation System (LDAS), of which there is a global collection (GLDAS)
and a North American collection (NLDAS), takes inputs of measurements like precipitation,
soil texture, topography, and leaf area index and then uses those inputs to model output estimates

of runoff and evapotranspiration:Research quality LDAS Total Runoff data are available in
Earthdata Search:Back to the TableModern-Era Retrospective analysis for Research and Applications
version 2 (MERRA-2) is the latest version of global atmospheric reanalysis for the satellite
era produced by NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth
Observing System Model (GEOS) version. The dataset covers the period of 1980-present with

the latency of approximately three weeks after the end of a month:Research quality MERRA-2
Total Runoff datasets are available in Earthdata Search:Back to the TableThe NASA Earth Exchange
Global Daily Downscaled Projections (NEX-GDDP) dataset is comprised of high-resolution, bias-corrected
global downscaled climate projections derived from the General Circulation Model (GCM) runs
conducted under the Coupled Model Intercomparison Project Phase 6 (CMIP6) and across all four

“Tier 1” greenhouse gas emissions scenarios known as Shared Socioeconomic Pathways (SSPs).
This dataset provides a set of global, high resolution, bias-corrected climate change projections
that can be used to evaluate climate change impacts on processes that are sensitive to finer-scale
climate gradients and the effects of local topography on climate conditions. Uses include:
air temperature, precipitation volume, humidity, stellar radiation, and atmospheric wind speed.NEX-GDDP-CMIP6

data are available through the NASA Center for Climate Simulation (NCCS):Back to the TableSeasonal
water runoff from snowpack and glaciers provide irrigation and drinking water for billions
of people worldwide. The Indus Basin in Asia, for example, is the largest irrigation system
in the world; snow melt from the Himalayan mountains is essential for rice production in the
basin and contributes significantly to agricultural irrigation. Changes in global snow cover

can have major impacts on food production.Snow Water Equivalent (SWE) is the amount of water
contained in snowpack. It is analogous to melting the snow and measuring the depth of the
resulting pool of water. SWE measurements are useful for assessing both the potential surface
runoff from snowmelt and the water availability for regions in lower elevations.An asterisk
(*) next to an entry indicating that near real-time (NRT) data products are available through

NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) within three hours from
satellite observation. Imagery is generally available 3-5 hours after observation. While not
intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical
events.1-2 days, 8 days, MonthlyNear real-time snow cover data can be interactively explored
using NASA Worldview:Research quality data products can be accessed using Earthdata Search:Near

real-time (NRT) MODIS snow cover data are available through LANCE 60 to 125 minutes after
a satellite observation. GIS layer displaying water states (ice, snow, water, etc.):Back to
the TableThe Advanced Microwave Scanning Radiometer (AMSR) for EOS (AMSR-E) instrument and
the AMSR-2 instrument provide SWE data.Near real-time data can be interactively explored using
NASA Worldview:Research quality data products can be accessed using Earthdata Search:Near

real-time (NRT) AMSR2 snow water equivalent data are available through LANCE 60 to 125 minutes
after a satellite observation. NASA's Airborne Snow Observatory (ASO) mission collects data
on snowmelt flowing out of major water basins in the Western U.S. The mission began in April
2013 as a collaboration between NASA's Jet Propulsion Laboratory (JPL) and the California
Department of Water Resources, with weekly flights over the Tuolumne River Basin in California

and monthly flights over the Uncompahgre River Basin in Colorado during the snowmelt season.
Current data collection is undertaken by Airborne Snow Observatories, Inc., a private company
working in partnership with Esri and the Weather Research and Forecasting Model Hydrological
modeling system (WRF-Hydro) team of the National Center for Atmospheric Research.Back to the
TableAnother NASA source for SWE data is Daymet, which can be accessed through NASA's ORNL

DAAC. Daymet is a collection of gridded estimates of daily weather parameters including minimum
and maximum temperature, precipitation, vapor pressure, radiation, snow water equivalent,
and day length at 1 km resolution over the North America, Puerto Rico, and Hawaii from 1980
to present (North America and Hawaii) and from 1950 to present (Puerto Rico). Back to the
TableNASA, in collaboration with other agencies, has developed models of snow cover and depth

that incorporate satellite information with ground-based data (when ground-based data are
available). These models are part of the Land Data Assimilation System (LDAS), which includes
a global collection (GLDAS) and a North American collection (NLDAS). Snow depth data products
are are available from Giovanni. These data can be visualized as a time-averaged map, an animation,
seasonally-averaged maps, scatter plots, or a time series using an online interactive data

analysis tool called Giovanni:GLDAS model data are available from NASA's GES DISC:Back to
the TableThe Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2)
provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data
can be used to look for trends and patterns, as well as anomalies. There are several options
available: hourly and monthly from 1980.MERRA -2 Snow data products can be visualized as a

time-averaged map, an animation, seasonally-averaged maps, scatter plots, or a time series
using a NASA interactive data analysis tool called Giovanni:Back to the TableSoil moisture
is vital for crop growth and yield, while extreme values (high or low) can negatively impact
crop growth. Timely seasonal soil moisture information enhances food security and provides
the ability to detect drought and other water-related stressors (such as root rot) on crop

production. Soil moisture datasets indicate the amount of water at a specific location in
the soil profile, based either on depth or infiltration time.An asterisk (*) next to an entry
indicating that near real-time (NRT) data products are available through NASA's Land, Atmosphere
Near real-time Capability for EOS (LANCE) within three hours from satellite observation. Imagery
is generally available 3-5 hours after observation. While not intended for scientific research,

NRT data are good resources for monitoring ongoing or time-critical events.NASA's Soil Moisture
Active Passive satellite (SMAP, launched in 2015) measures the moisture in the top 5 cm of
soil globally daily and every 2-3 days at a resolution of 9-36 km. Near real-time SMAP imagery
can be interactively explored using NASA Worldview:Research quality data products can be accessed
using Earthdata Search:Near real-time (NRT) SMAP data are available through NASA’s Land, Atmosphere

Near real-time Capability for EOS (LANCE) within 60 to 125 minutes after a satellite observation:Back
to the TableThe Advanced Microwave Scanning Radiometer (AMSR) for EOS (AMSR-E) instrument
and the AMSR-2 instrument provide volumetric soil moisture data. AMSR2 provides global passive
microwave measurements of Surface Soil Moisture. Near real-time (NRT) products are generated
within 3 hours of the last observations in the file. Data can be visualized using NASA Worldview:Data

products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots,
or a time series using a NASA interactive tool called Giovanni:Near-real time data:Research-quality
data products can be accessed using Earthdata Search:Back to the TableThe Short-term Prediction
Research and Transition (SPoRT) project at NASA's Marshall Space Flight Center in Huntsville,
AL, is a NASA- and NOAA-funded activity to transition experimental/ quasi-operational satellite

observations and research capabilities to the operational weather community to improve short-term
weather forecasts on a regional and local scale.Short-term Prediction Research and Transition-Land
Information System (SPoRT-LiS) provides real-time 3km Land Information System data on the
following parameters: Volumetric Soil Moisture, Relative Soil Moisture, Column-Integrated
Relative Soil Moisture, and Green Vegetation Fraction.SPoRT offers a Near Real-Time Viewer

that includes SMAP datasets for the following regions:Back to the TableNASA, in collaboration
with other agencies, has developed models of soil moisture content that incorporate satellite
information with ground-based data (when ground-based data are available). These models are
part of the Land Data Assimilation System (LDAS), which includes a global collection (GLDAS)
and a North American collection (NLDAS). LDAS takes inputs of measurements like precipitation,

soil texture, topography, and leaf area index and uses these inputs to model output estimates
of soil moisture and evapotranspiration.The NLDAS experimental drought monitor is derived
from near real-time soil moisture output model data: Soil MERGE (SMERGE) is a root-zone soil
moisture product developed by merging NLDAS land surface model output with surface satellite
retrievals from the ESA (European Space Agency) Climate Change Initiative. This data product

contains root-zone soil moisture of 0-40 cm layer, Climate Change Initiative (CCI)-derived
soil moisture anomalies of 0-40 cm layer, and a soil moisture data estimation flag:NLDAS,
GLDAS, and SMERGE data products can be visualized as a time-averaged map, an animation, seasonally-averaged
maps, scatter plots, or a time series using a NASA interactive data analysis tool called Giovanni:LDAS
Soil Moisture data from GLDAS, NLDAS and FLDAS are available in Earthdata Search:Back to the

TableWeekly soil moisture and groundwater drought indicators are available each week based
on terrestrial water storage observations derived from GRACE satellite data and integrated
with other observations, using a sophisticated numerical model of land surface water and energy
processes, referred to as GRACE Data Assimilation for Drought Monitoring (GRACE-DA-DM):Back
to the TableNASA’S Global Modeling And Assimilation Office (GMAO), in collaboration with The

University of Montana and the NASA Jet Propulsion Laboratory, provides value-added Level-4
data products. These Level-4 datasets rely on the merger of SMAP observations into physically-based
numerical models of the land surface water, energy, and carbon cycles. Available Level-4 data
include global, 9-km, 3-hourly estimates of surface and root zone soil moisture, surface and
soil temperature, and land surface fluxes, along with algorithm diagnostics from the ensemble-based

data assimilation system. Level-4 data further include global, 9-km, daily estimates of net
ecosystem CO2 exchange, component carbon stocks and fluxes, and sub-grid information broken
down by plant functional types.Near real-time SMAP imagery can be interactively explored using
NASA Worldview:These data products are available from Earthdata Search:Back to the TableThe
Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides

data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be
used to look for trends and patterns, as well as anomalies. There are several options available:
hourly and monthly from 1980.MERRA -2 Soil Moisture data products can be visualized as a time-averaged
map, an animation, seasonally-averaged maps, scatter plots, or a time series using a NASA
interactive data analysis tool called Giovanni:MERRA-2 Soil Moisture data in Earthdata Search:Water

budgets for individual watersheds can be estimated using remote sensing data for precipitation,
evapotranspiration, and runoff. Terra and Aqua MODIS Water Reservoir data products provide
a monthly time series of reservoir area, elevation, storage capacity, evaporation rate, and
evaporation volume for 151 human-created reservoirs and 13 regulated natural lakes worldwide.
These data products are available through Earthdata Search:GIS layer displaying water states

(ice, snow, water, etc.):The Global Reservoir and Dam (GRanD) dataset, provided by NASA’s
Socioeconomic Data and Applications Center (SEDAC),displays the location of dams and water
reservoirs around the world as feature points:For more information on additional data resources
on water resources, visit the Sea Level Change Data Pathfinder.NASA satellites, airplanes,
and ground stations collect data on events like rainfall, drought, and other extreme weather

events—data that are critical for informing agricultural decisions and policy.Humidity is
a measure of the amount of water vapor present in the air. High humidity impairs heat exchange
efficiency by reducing the rate of moisture evaporation from the skin and other surfaces.
This can create challenges for agricultural workers, as well as the crops they grow. Data,
often in near real-time (NRT), can be visualized using NASA Worldview:Data products can be

visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series
using a NASA interactive tool called Giovanni:Research-quality data products can be accessed
using Earthdata Search:Back to the TableThe Modern-Era Retrospective analysis for Research
and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of
historical data available, MERRA-2 data can be used to look for trends and patterns as well

as anomalies. There are several options available: 1-hourly, 3-hourly, 6-hourly, daily, and
monthly. These options provide information on precipitation.Data, often in near real-time
(NRT), are available for visualization using NASA Worldview:Data products can be visualized
as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series using
a NASA interactive tool called Giovanni:Research-quality data products can be accessed using

Earthdata Search:The NASA Prediction of Worldwide Energy Resources (POWER) Data Access Viewer
provides MERRA-2 meteorological parameters through a web mapping application with the capability
for data subsetting, charting, and visualizing. The data are also available via API, GIS enabled,
as well as via OPeNDAP.Back to the TableThe NASA Earth Exchange Global Daily Downscaled Projections
(NEX-GDDP) dataset is comprised of high-resolution, bias-corrected global downscaled climate

projections derived from the General Circulation Model (GCM) runs conducted under the Coupled
Model Intercomparison Project Phase 6 (CMIP6) and across all four “Tier 1” greenhouse gas
emissions scenarios known as Shared Socioeconomic Pathways (SSPs). This dataset provides a
set of global, high resolution, bias-corrected climate change projections that can be used
to evaluate climate change impacts on processes that are sensitive to finer-scale climate

gradients and the effects of local topography on climate conditions. Uses include: air temperature,
precipitation volume, humidity, stellar radiation, and atmospheric wind speed.NEX-GDDP-CMIP6
data are available through the NASA Center for Climate Simulation (NCCS).Back to the TableRain
and snow provide the water upon which agriculture depends, either directly (via rain or snowfall
directly on fields) or indirectly (through water reserves that are used for irrigation). Understanding

how this water is distributed and how it changes is essential to food security and sustainable
water usage.An asterisk (*) next to an entry indicating that near real-time (NRT) data products
are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) within
three hours from satellite observation. Imagery is generally available 3-5 hours after observation.
While not intended for scientific research, NRT data are good resources for monitoring ongoing

or time-critical events. HDF, netCDF, GeoTIFFNorth America, Hawaii: 1980-presentPuerto Rico:
1950-presentThe Advanced Microwave Scanning Radiometer 2 (AMSR-2) instrument collects data
that indicate the rate at which precipitation is falling on the ocean surface in millimeters
per hour (mm/hr). Data can be visualized using NASA Worldview:Research-quality data products
can be accessed using Earthdata Search:Near real-time (NRT) AMSR-2 Surface Precipitation products

are generated by the Land Atmosphere Near real-time Capability for EOS (LANCE). NRT products
are generated in HDF-EOS-5 augmented with netCDF-4/CF metadata and are available via HTTPS
from LANCE. If data latency is not a primary concern, please consider using science quality
products, which are created using the best available ancillary, calibration, and ephemeris
information.Back to the TableNASA's Precipitation Measurement Missions (PMM) provide a continuous

record of precipitation data through the Tropical Rainfall Measuring Mission (TRMM; operational
1997 to 2015) and the Global Precipitation Measurement mission (GPM; launched in 2014). GPM,
the TRMM successor mission, provides more accurate measurements, improved detection of light
rain and snow, and extended spatial coverage.IMERGData products from TRMM and GPM are available
individually and have been integrated with data from a global constellation of satellites

to yield precipitation estimates with improved spatial coverage and temporal resolution. The
first integrated product was the TRMM Multi-satellite Precipitation Analysis (TMPA), which
has been superseded by the Integrated Multi-satellitE Retrievals for GPM (IMERG). IMERG's
multiple runs accommodate different user requirements for accuracy and latency (Early = 4
hours, e.g., for flash flood events; Late = 12 hours, e.g., for crop forecasting; and Final

= 3 months, with the incorporation of rain gauge data, for research). Along with Earthdata
Search, IMERG data are available through NASA's GPM website.GPM data can be visualized using
NASA Worldview:The Short-term Prediction Research and Transition (SPoRT) project at NASA's
Marshall Space Flight Center in Huntsville, AL, is a NASA- and NOAA-funded activity to transition
experimental/ quasi-operational satellite observations and research capabilities to the operational

weather community to improve short-term weather forecasts on a regional and local scale. SPoRT
offers a Near Real-Time Viewer for IMERG data:Users may access and visualize these data directly
through ClimateSERV. Additional datasets include IMERG, Evaporative Stress Index, SMAP Soil
Moisture, Rainfall, and NDVI.Data products can be visualized as a time-averaged map, an animation,
seasonal maps, scatter plots, or a time series through Giovanni:Near-real time (NRT) data:Research-quality

data products can be accessed using Earthdata Search:Back to the TableSERVIR (a joint initiative
of NASA, USAID, and geospatial organizations in Asia, Africa, and Latin America) and the Climate
Hazards Group (CHG) at University of California at Santa Barbara have developed an improved
rainfall forecast dataset that merges two highly recognized datasets: Climate Hazards Group
InfraRed Precipitation with Station (CHIRPS) and the NCEP’s Global Ensemble Forecasting System

(GEFS). GEFS is a weather forecast system that provides daily forecasts out to 16 days at
1 X 1 degree resolution at 6-hour intervals.The combined CHIRPS-GEFS dataset uses the higher
spatial resolution of CHIRPS and the advanced forecasting ability of GEFS to provide up to
a 16-day forecast updated every five days at a global spatial resolution of 5 km. CHIRPS-GEFS
model data are available for analysis and download through SERVIR's Product Catalog. Users

may access and visualize these data directly through ClimateSERV. Additional datasets include
IMERG, Evaporative Stress Index, SMAP Soil Moisture, Rainfall, and NDVI.Back to the TableAnother
NASA source for precipitation data is Daymet, which can be accessed through NASA's Oak Ridge
National Laboratory Distributed Active Archive Center (ORNL DAAC). Daymet is a collection
of gridded estimates of daily weather parameters including minimum and maximum temperature,

precipitation, vapor pressure, radiation, snow water equivalent, and day length at 1 km resolution
over North America, Puerto Rico, and Hawaii. Daymet data are available from 1980 to present
(North America and Hawaii) and from 1950 to present (Puerto Rico) and can be retrieved in
a variety of ways, including: Earthdata Search; an API available through ORNL DAAC; ORNL DAAC
tools; and through the Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)

application. Along with daily data, annual Daymet climatologies also are available.Back to
the TableThe Land Data Assimilation System (LDAS) includes a global collection (GLDAS) and
a North American collection (NLDAS). LDAS uses measurements including air temperature, precipitation,
soil texture, topography, and leaf area index to model high quality fields of land surface
states (e.g., soil moisture, temperature) and fluxes (e.g., evapotranspiration, runoff). GLDAS

modeled data are available from January 1948 to present. NLDAS modeled datasets are available
from January 1979 to present.Data can be visualized using NASA Worldview:Back to the TableThe
Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides
data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be
used to look for trends and patterns as well as anomalies. There are several options available:

1-hourly, 3-hourly, 6-hourly, daily, and monthly. These options provide information on precipitation.Data,
often in near real-time (NRT), are available for visualization using NASA Worldview:Data products
can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a
time series using Giovanni:Research-quality air surface temperature data products can be accessed
using Earthdata Search:The NASA Prediction of Worldwide Energy Resources (POWER) Data Access

Viewer provides MERRA-2 meteorological parameters through a web mapping application with the
capability for data subsetting, charting, and visualizing. The data are also available via
API as well as via OPeNDAP.Back to the TableSurface Air Temperature (SAT) generally refers
to the air temperature generally measured at approximately 6.5 feet (about 2 meters) above
the ground or ocean surface. Surface air temperature provides a key indicator of climate change,

contributing to the “global surface temperature record”. SAT (along with other factors like
soil moisture, soil type, etc.) affects soil temperatures, which can impact crop development
and productivity.North America, Hawaii: 1980-presentPuerto Rico: 1950-presentThe Atmospheric
Infrared Sounder (AIRS) provides 3D measurements of temperature, water vapor, trace gases,
and surface and cloud properties through the atmospheric column.Data, often in near real-time

(NRT), are available for visualization using NASA Worldview:Data products can be visualized
as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series using
Giovanni:Research-quality air surface temperature data products can be accessed using Earthdata
Search:AIRS NRT data are available from NASA’s Land, Atmosphere Near real-time Capability
for EOS (LANCE) 75 to 140 minutes after a satellite observation.Back to the TableThe Land

Data Assimilation System (LDAS) includes a global collection (GLDAS) and a North American
collection (NLDAS). LDAS uses measurements including air temperature, precipitation, soil
texture, topography, and leaf area index to model high quality fields of land surface states
(e.g., soil moisture, temperature) and fluxes (e.g., evapotranspiration, runoff).GLDAS data
are available from January 1948 to present. Retrospective hourly/monthly NLDAS datasets are

available from January 1979 to present.Monthly data can be visualized using NASA Worldview:Data
products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots,
or a time series using Giovanni:The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries.The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models. FLDAS data can be visualized as time-averaged maps, animations, seasonally-averaged
maps, scatter plots, or time series using a NASA interactive data analysis tool called Giovanni:Back
to the TableThe Modern-Era Retrospective analysis for Research and Applications, Version 2
(MERRA-2) provides data beginning in 1980. Due to the amount of historical data available,

MERRA-2 data can be used to look for trends and patterns as well as anomalies. There are several
options available: 1-hourly, 3-hourly, 6-hourly. These options provide information on surface
skin temperature, air temperature at 2 m, and air temperature at 10 m.Data, often in near
real-time (NRT), are available for visualization using NASA Worldview:Data products can be
visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series

using Giovanni:Research-quality air surface temperature data products can be accessed using
Earthdata Search:Back to the TableThe NASA Earth Exchange Global Daily Downscaled Projections
(NEX-GDDP) dataset is comprised of high-resolution, bias-corrected global downscaled climate
projections derived from the General Circulation Model (GCM) runs conducted under the Coupled
Model Intercomparison Project Phase 6 (CMIP6) and across all four “Tier 1” greenhouse gas

emissions scenarios known as Shared Socioeconomic Pathways (SSPs). This dataset provides a
set of global, high resolution, bias-corrected climate change projections that can be used
to evaluate climate change impacts on processes that are sensitive to finer-scale climate
gradients and the effects of local topography on climate conditions. Uses include: air temperature,
precipitation volume, humidity, stellar radiation, and atmospheric wind speed.NEX-GDDP-CMIP6

data are available through the NASA Center for Climate Simulation (NCCS).Back to the TableAnother
NASA source for air temperature modeled data is Daymet. Daymet is a collection of gridded
estimates of daily weather parameters including minimum and maximum temperature, precipitation,
vapor pressure, radiation, snow water equivalent, and day length at 1 km resolution over North
America, Puerto Rico, and Hawaii. Daymet data are available from 1980 to present (North America

and Hawaii) and from 1950 to present (Puerto Rico).Research-quality air surface temperature
data products can be accessed using Earthdata Search:Back to the TableWeather maps produced
from model data and satellite observations can be used to create medium and long-range forecasts
of temperature, humidity, precipitation, and more.To support NASA’s satellite missions and
field experiments, NASA's Global Modeling and Assimilation Office (GMAO) generates near-real

time atmospheric products using model data from the Goddard Earth Observing System (GEOS)
and distributes them to a broad community of users. The GEOS "Forward Processing" (FP) system
generates analyses, assimilation products, and 10-day forecasts with the most up-to-date validated
version of GEOS that is available. Available forecast parameters include precipitation, humidity,
wind speed, and temperature.Visit the sections below to find resources that help you explore

weather maps and models.GEOS-5 Weather Maps: Within the viewer, select the parameter or field
of interest, the area of interest, and then indicate the forecast time and the forecast lead
hourAn estimated 720 and 811 million people in the world faced hunger in 2020, according to
the United Nations (UN), and nearly one in three people in the world (2.37 billion) did not
have access to adequate food in 2020. The vulnerabilities and inadequacies of global food

systems are expected to further intensify over the coming years. The combination of NASA Earth
science data with socioeconomic data provides key information for sustainable use of available
resources.NASA's Socioeconomic Data and Applications Center (SEDAC) is the home for NASA socioeconomic
data and is a gateway between the social sciences and the Earth sciences. SEDAC provides numerous
datasets and data collections that may be useful for studies into agriculture and water management.

SEDAC also provides information about the connections that support efforts to end hunger,
achieve food security and improved nutrition, and promote sustainable agriculture.NASA helps
develop tools to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. Much of this work is carried
out and supported fully or in part by the agency's Applied Sciences Program, which works with
individuals and institutions worldwide to inform decision-making, enhance quality of life,
and strengthen the economy. The Applied Sciences Program co-leads the international Earth
Observations for Sustainable Development Goals initiative, which advances global knowledge

about effective ways that Earth observations and geospatial information can support the SDGs.The
NASA datasets and resources listed below, coupled with other data and resources in this Data
Pathfinder, also help measure progress toward meeting United Nations’ Sustainable Development
Goals (SDGs), particularly SDG 2: Zero Hunger. These data can provide a better overall view
for monitoring the food insecurity of vulnerable populations, tracking agricultural production

related to incomes of small-scale food producers, and monitoring environmental impacts to
soil, water, fertilizer, pesticide pollution, and changes in biodiversity. More information
is available in the Connection of Sustainable Development Goals to Agriculture and Water Management
section on the main Pathfinder landing page. NASA satellites, airplanes, and ground stations
collect data on events like rainfall, drought, and other extreme weather events—data that

are critical for informing agricultural decisions and policy. Humidity is a measure of the
amount of water vapor present in the air. High humidity impairs heat exchange efficiency by
reducing the rate of moisture evaporation from the skin and other surfaces. This can create
challenges for agricultural workers, as well as the crops they grow. Rain and snow provide
the water upon which agriculture depends, either directly (via rain or snowfall directly on

fields) or indirectly (through water reserves that are used for irrigation). Understanding
how this water is distributed and how it changes is essential to food security and sustainable
water usage. Surface Air Temperature (SAT) generally refers to the air temperature generally
measured at approximately 6.5 feet (about 2 meters) above the ground or ocean surface. Surface
air temperature provides a key indicator of climate change, contributing to the “global surface

temperature record”. SAT (along with other factors like soil moisture, soil type, etc.) affects
soil temperatures, which can impact crop development and productivity. Surface Air Temperature
(SAT) generally refers to the air temperature generally measured at approximately 6.5 feet
(about 2 meters) above the ground or ocean surface. Surface air temperature provides a key
indicator of climate change, contributing to the “global surface temperature record”. SAT

(along with other factors like soil moisture, soil type, etc.) affects soil temperatures,
which can impact crop development and productivity.The layered structure of Earth's atmosphere
is visible in this sunset view from the International Space Station.Image Science & Analysis
Laboratory, NASA Johnson Space CenterThe atmosphere is a mixture of gases that surrounds the
Earth. It helps make life possible by providing us with air to breathe, shielding us from

harmful ultraviolet (UV) radiation coming from the Sun, trapping heat to warm the planet,
and preventing extreme temperature differences between day and night. Without the atmosphere,
temperatures would be well below freezing everywhere on Earth's surface. Instead, the heat
absorbed and trapped by our atmosphere keeps our planet's average surface temperature at a
balmy 15°C (59°F). Some of the atmosphere's gases, like carbon dioxide, are particularly good

at absorbing and trapping radiation. Changes in the amounts of these gases directly affect
our climate.Each of the planets in our solar system has an atmosphere, but none of them have
the same ratio of gases or layered structure as Earth's atmosphere. Nitrogen and oxygen are
by far the most common gases in our atmosphere. Dry air is composed of about 78% nitrogen
(N2) and about 21% oxygen (O2). The remaining less than 1% of the atmosphere is a mixture

of gases, including argon (Ar) and carbon dioxide (CO2). The atmosphere also contains varying
amounts of water vapor, on average about 1%. There are also many, tiny, solid or liquid particles,
called aerosols, in the atmosphere. Aerosols can be made of dust, spores and pollen, salt
from sea spray, volcanic ash, smoke, and pollutants introduced through human activity.The
atmosphere becomes thinner (less dense and lower in air pressure) the further it extends from

the Earth's surface. It gradually gives way to the vacuum of space. There is no precise top
of the atmosphere, but the area between 100-120 km (62-75 miles) above the Earth's surface
is often considered the boundary between the atmosphere and space because the air is so thin
here. However, there are measurable traces of atmospheric gases beyond this boundary, detectable
for hundreds of kilometers/miles from Earth's surface.There are several unique layers in Earth's

atmosphere. Each has characteristic temperatures, pressures, and phenomena. We live in the
troposphere, the layer closest to Earth's surface, where most clouds are found and almost
all weather occurs. Some jet aircraft fly in the next layer, the stratosphere, which contains
the jet streams and a region called the ozone layer. The next layer, the mesosphere, is the
coldest because the there are almost no air molecules there to absorb heat energy. There are

so few molecules for light to refract off of that the sky also changes from blue to black
in this layer. And farthest from the surface we have the thermosphere, which absorbs much
of the harmful radiation that reaches Earth from the Sun, causing this layer to reach extremely
high temperatures. Beyond the thermosphere is the exosphere, which represents the transition
from Earth's atmosphere to space. Earth is not the only world with an atmosphere. Each of

the planets - and even a few moons - in our solar system have an atmosphere. Some planets
have active atmospheres with clouds, wind, rain and powerful storms. Scientists use light
spectroscopy to observe the atmospheres of planets and moons in other solar systems .Each
of the planets in our solar system has a uniquely structured atmosphere. The atmosphere of
Mercury is extremely thin and is not very different from the vacuum of space. The gas giant

planets in our solar system - Jupiter, Saturn, Uranus and Neptune - each have a thick, deep
atmosphere. The smaller, rocky planets - Earth, Venus and Mars - each have thinner atmospheres,
hovering above their solid surfaces. The moons in our solar system typically have thin atmospheres,
with the exception of Saturn's moon, Titan. Air pressure at the surface of Titan is higher
than on Earth! Of the five officially recognized dwarf planets, Pluto has a thin atmosphere

that expands and collapses seasonally, and Ceres has an extremely thin and transient atmosphere
made of water vapor.But only Earth's atmosphere has the layered structure that traps enough
of the Sun's energy for warmth while also blocking much of the harmful radiation from the
Sun. This important balance is necessary to maintain life on Earth. © 2021 UCAR© 2023 UCARThis
material is based upon work supported by the National Center for Atmospheric Research, a major

facility sponsored by the National Science Foundation and managed by the University Corporation
for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed
in this material do not necessarily reflect the views of the National Science Foundation.
Surface Air Temperature (SAT) generally refers to the air temperature generally measured at
approximately 6.5 feet (about 2 meters) above the ground or ocean surface. Surface air temperature

provides a key indicator of climate change, contributing to the “global surface temperature
record”. SAT (along with other factors like soil moisture, soil type, etc.) affects soil temperatures,
which can impact crop development and productivity.The layered structure of Earth's atmosphere
is visible in this sunset view from the International Space Station.Image Science & Analysis
Laboratory, NASA Johnson Space CenterThe atmosphere is a mixture of gases that surrounds the

Earth. It helps make life possible by providing us with air to breathe, shielding us from
harmful ultraviolet (UV) radiation coming from the Sun, trapping heat to warm the planet,
and preventing extreme temperature differences between day and night. Without the atmosphere,
temperatures would be well below freezing everywhere on Earth's surface. Instead, the heat
absorbed and trapped by our atmosphere keeps our planet's average surface temperature at a

balmy 15°C (59°F). Some of the atmosphere's gases, like carbon dioxide, are particularly good
at absorbing and trapping radiation. Changes in the amounts of these gases directly affect
our climate.Each of the planets in our solar system has an atmosphere, but none of them have
the same ratio of gases or layered structure as Earth's atmosphere. Nitrogen and oxygen are
by far the most common gases in our atmosphere. Dry air is composed of about 78% nitrogen

(N2) and about 21% oxygen (O2). The remaining less than 1% of the atmosphere is a mixture
of gases, including argon (Ar) and carbon dioxide (CO2). The atmosphere also contains varying
amounts of water vapor, on average about 1%. There are also many, tiny, solid or liquid particles,
called aerosols, in the atmosphere. Aerosols can be made of dust, spores and pollen, salt
from sea spray, volcanic ash, smoke, and pollutants introduced through human activity.The

atmosphere becomes thinner (less dense and lower in air pressure) the further it extends from
the Earth's surface. It gradually gives way to the vacuum of space. There is no precise top
of the atmosphere, but the area between 100-120 km (62-75 miles) above the Earth's surface
is often considered the boundary between the atmosphere and space because the air is so thin
here. However, there are measurable traces of atmospheric gases beyond this boundary, detectable

for hundreds of kilometers/miles from Earth's surface.There are several unique layers in Earth's
atmosphere. Each has characteristic temperatures, pressures, and phenomena. We live in the
troposphere, the layer closest to Earth's surface, where most clouds are found and almost
all weather occurs. Some jet aircraft fly in the next layer, the stratosphere, which contains
the jet streams and a region called the ozone layer. The next layer, the mesosphere, is the

coldest because the there are almost no air molecules there to absorb heat energy. There are
so few molecules for light to refract off of that the sky also changes from blue to black
in this layer. And farthest from the surface we have the thermosphere, which absorbs much
of the harmful radiation that reaches Earth from the Sun, causing this layer to reach extremely
high temperatures. Beyond the thermosphere is the exosphere, which represents the transition

from Earth's atmosphere to space. Earth is not the only world with an atmosphere. Each of
the planets - and even a few moons - in our solar system have an atmosphere. Some planets
have active atmospheres with clouds, wind, rain and powerful storms. Scientists use light
spectroscopy to observe the atmospheres of planets and moons in other solar systems .Each
of the planets in our solar system has a uniquely structured atmosphere. The atmosphere of

Mercury is extremely thin and is not very different from the vacuum of space. The gas giant
planets in our solar system - Jupiter, Saturn, Uranus and Neptune - each have a thick, deep
atmosphere. The smaller, rocky planets - Earth, Venus and Mars - each have thinner atmospheres,
hovering above their solid surfaces. The moons in our solar system typically have thin atmospheres,
with the exception of Saturn's moon, Titan. Air pressure at the surface of Titan is higher

than on Earth! Of the five officially recognized dwarf planets, Pluto has a thin atmosphere
that expands and collapses seasonally, and Ceres has an extremely thin and transient atmosphere
made of water vapor.But only Earth's atmosphere has the layered structure that traps enough
of the Sun's energy for warmth while also blocking much of the harmful radiation from the
Sun. This important balance is necessary to maintain life on Earth. © 2021 UCAR© 2023 UCARThis

material is based upon work supported by the National Center for Atmospheric Research, a major
facility sponsored by the National Science Foundation and managed by the University Corporation
for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed
in this material do not necessarily reflect the views of the National Science Foundation.Find
and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections

between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing

numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The

land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based

measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have

the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Forests are one of the world’s largest
banks of carbon-rich biomass. This is why when researchers mapped biomass in the past, they

typically focused on the world’s forests. But this approach leaves out considerable amounts
of biomass in grasslands, shrublands, croplands, and other biomes. New maps, published at
NASA's Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) and described
in Nature Scientific Data, combine remotely sensed biomass data for different land cover types
into harmonized global maps of above and belowground biomass for the year 2010.“People often

conflate forest biomass with total biomass,” said Seth Spawn, lead author of the research
and doctoral candidate at the University of Wisconsin, Madison. “Researchers have spent a
lot of time developing nice remotely sensed maps of aboveground forest biomass, but they intentionally
omit other land covers and the carbon stored below ground in plant roots. We haven’t had the
whole picture.”Spawn and his team combined maps of forest biomass with other land cover specific

biomass maps that use remotely sensed data. They allocated fractional contributions to a given
grid cell using data on land cover, percent tree cover, and the presence of secondary vegetation.
These maps show a sizable stock of biomass outside of forested areas, especially in the trees
located in savannas and farm fields.“There’s more carbon on croplands than I would have expected,”
said Spawn. Trees on orchards and farms practicing agroforestry have a carbon stock that is

overlooked in previous biomass maps. Globally, trees on croplands stored about 28 metric gigatons
of carbon in 2010, which is 7 percent of the total stock of carbon in plants, according to
these new maps.The team produced maps of uncertainty with the data they used and published
them along with the dataset.Published in March, the dataset is already being used for a number
of applications. Researchers are using the dataset in integrated assessment models that incorporate

economics and the Earth system. It is also being used to model carbon emissions from past
and potential land use changes and the carbon impacts of bioenergy transitions.Spawn and colleagues
also used preliminary findings from this research to identify places with high carbon stocks
and biodiversity. “There are certain areas, the ‘hotspots,’ where biodiversity and carbon
density align,” Spawn said. “Identifying these areas can help governments and resource managers

prioritize land for protection.”Read more about the data in Nature Scientific Data. You can
download the data, Global Aboveground and Belowground Biomass Carbon Density Maps for the
Year 2010, from Earthdata Search or ORNL DAAC.NASA provides unrestricted access to air quality
data Water is a key component of the overall Earth system, cycling through each component,
moving within the atmosphere, the ocean, the cryosphere (including snow cover and snowpack),

surface water of rivers and lakes, and subsurface water. Water availability is critical for
human consumption, agriculture and food security, industry, and energy development. Assessing
water availability, including the amount and type of precipitation is critical to monitoring
agricultural practices and water resource availability and for providing interventions when
necessary. According to the U.N., water use has been growing globally at twice the rate as

the global population is increasing. More and more areas are reaching the limit at which water
services can be sustainably delivered, especially in arid regions. Groundwater, a major water
resource for maintaining cropland productivity, is declining through the extensive use of
water for agricultural irrigation, where aquifer recharge cannot keep up with groundwater
extraction. Unfortunately, changes in terrestrial water storage, especially with regard to

groundwater, are poorly known and sparsely sampled. Complicating matters further, global freshwater
is not only unevenly distributed, but sources of freshwater such as lakes and rivers often
cross geopolitical boundaries. Integrating satellite data with land-based and other measurements,
geospatial data, and hydrologic models help to better understand controls on global water
resources and how changing water resources impact social-environmental systems across geopolitical

boundaries. Surface runoff is the volume of available surface water after a precipitation
event that has been partitioned into evapotranspiration (ET) and stored as soil moisture.
This available water may be used for irrigation, domestic use, and for livestock. Droughts
are indicated by lower surface runoff anomaly values showing that water reservoirs have received
less than normal amounts of surface runoff. Elevated total runoff anomaly values may indicate

flooding events and have lasting impacts on crops, livestock, and residents. Seasonal water
runoff from snowpack and glaciers provide irrigation and drinking water for billions of people
worldwide. The Indus Basin in Asia, for example, is the largest irrigation system in the world;
snow melt from the Himalayan mountains is essential for rice production in the basin and contributes
significantly to agricultural irrigation. Changes in global snow cover can have major impacts

on food production. Snow Water Equivalent (SWE) is the amount of water contained in snowpack.
It is analogous to melting the snow and measuring the depth of the resulting pool of water.
SWE measurements are useful for assessing both the potential surface runoff from snowmelt
and the water availability for regions in lower elevations. Soil moisture is vital for crop
growth and yield, while extreme values (high or low) can negatively impact crop growth. Timely

seasonal soil moisture information enhances food security and provides the ability to detect
drought and other water-related stressors (such as root rot) on crop production. Soil moisture
datasets indicate the amount of water at a specific location in the soil profile, based either
on depth or infiltration time. Water budgets for individual watersheds can be estimated using
remote sensing data for precipitation, evapotranspiration, and runoff. Water budgets for individual

watersheds can be estimated using remote sensing data for precipitation, evapotranspiration,
and runoff.Find and use NASA Earth science data fully, openly, and without restrictions.Recognizing
the connections between interdependent Earth systems is critical for understanding the world
in which we live.The atmosphere is a gaseous envelope surrounding and protecting our planet
from the intense radiation of the Sun and serves as a key interface between the terrestrial

and ocean cycles.The biosphere encompasses all life on Earth and extends from root systems
to mountaintops and all depths of the ocean. It is critical for maintaining species diversity,
regulating climate, and providing numerous ecosystem functions.The cryosphere encompasses
the frozen parts of Earth, including glaciers and ice sheets, sea ice, and any other frozen
body of water. The cryosphere plays a critical role in regulating climate and sea levels.The

human dimensions discipline includes ways humans interact with the environment and how these
interactions impact Earth’s systems. It also explores the vulnerability of human communities
to natural disasters and hazards.The land surface discipline includes research into areas
such as shrinking forests, warming land, and eroding soils. NASA data provide key information
on land surface parameters and the ecological state of our planet.This vast, critical reservoir

supports a diversity of life and helps regulate Earth’s climate.Processes occurring deep within
Earth constantly are shaping landforms. Although originating from below the surface, these
processes can be analyzed from ground, air, or space-based measurements.The Sun influences
a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on

the land surface and underground in the form of lakes, rivers, and groundwater along with
total water storage.Whether you are a scientist, an educator, a student, or are just interested
in learning more about NASA’s Earth science data and how to use them, we have the resources
to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making

NASA's free and open Earth science data interactive, interoperable, and accessible for research
and societal benefit both today and tomorrow.Remote sensing is the acquiring of information
from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites
and aircraft that detect and record reflected or emitted energy. Remote sensors, which provide
a global perspective and a wealth of data about Earth systems, enable data-informed decision

making based on the current and future state of our planet.For more information, check out
NASA's Interagency Implementation and Advanced Concepts Team (IMPACT) Tech Talk: From Pixels
to Products: An Overview of Satellite Remote Sensing.Satellites can be placed in several types
of orbits around Earth. The three common classes of orbits are low-Earth orbit (approximately
160 to 2,000 km above Earth), medium-Earth orbit (approximately 2,000 to 35,500 km above Earth),

and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting at 35,786 km are at
an altitude at which their orbital speed matches the planet's rotation, and are in what is
called geosynchronous orbit (GSO). In addition, a satellite in GSO directly over the equator
will have a geostationary orbit. A geostationary orbit enables a satellite to maintain its
position directly over the same place on Earth’s surface.Low-Earth orbit is a commonly used

orbit since satellites can follow several orbital tracks around the planet. Polar-orbiting
satellites, for example, are inclined nearly 90 degrees to the equatorial plane and travel
from pole to pole as Earth rotates. This enables sensors aboard the satellite to acquire data
for the entire globe rapidly, including the polar regions. Many polar-orbiting satellites
are considered Sun-synchronous, meaning that the satellite passes over the same location at

the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting satellite
is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous

low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth

orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each

observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These

waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation

is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.

Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The

ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.

Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use

the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are

designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud

cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles

of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There

are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values

are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging

Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution

is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information

in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal

resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and

Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable

features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal

resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led

Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical

Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,

bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined

to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,

such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization

Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.

There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.

The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors

measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.

Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats. Water budgets
for individual watersheds can be estimated using remote sensing data for precipitation, evapotranspiration,
and runoff.Find and use NASA Earth science data fully, openly, and without restrictions.Recognizing

the connections between interdependent Earth systems is critical for understanding the world
in which we live.The atmosphere is a gaseous envelope surrounding and protecting our planet
from the intense radiation of the Sun and serves as a key interface between the terrestrial
and ocean cycles.The biosphere encompasses all life on Earth and extends from root systems
to mountaintops and all depths of the ocean. It is critical for maintaining species diversity,

regulating climate, and providing numerous ecosystem functions.The cryosphere encompasses
the frozen parts of Earth, including glaciers and ice sheets, sea ice, and any other frozen
body of water. The cryosphere plays a critical role in regulating climate and sea levels.The
human dimensions discipline includes ways humans interact with the environment and how these
interactions impact Earth’s systems. It also explores the vulnerability of human communities

to natural disasters and hazards.The land surface discipline includes research into areas
such as shrinking forests, warming land, and eroding soils. NASA data provide key information
on land surface parameters and the ecological state of our planet.This vast, critical reservoir
supports a diversity of life and helps regulate Earth’s climate.Processes occurring deep within
Earth constantly are shaping landforms. Although originating from below the surface, these

processes can be analyzed from ground, air, or space-based measurements.The Sun influences
a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on
the land surface and underground in the form of lakes, rivers, and groundwater along with
total water storage.Whether you are a scientist, an educator, a student, or are just interested

in learning more about NASA’s Earth science data and how to use them, we have the resources
to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making
NASA's free and open Earth science data interactive, interoperable, and accessible for research
and societal benefit both today and tomorrow.Remote sensing is the acquiring of information

from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites
and aircraft that detect and record reflected or emitted energy. Remote sensors, which provide
a global perspective and a wealth of data about Earth systems, enable data-informed decision
making based on the current and future state of our planet.For more information, check out
NASA's Interagency Implementation and Advanced Concepts Team (IMPACT) Tech Talk: From Pixels

to Products: An Overview of Satellite Remote Sensing.Satellites can be placed in several types
of orbits around Earth. The three common classes of orbits are low-Earth orbit (approximately
160 to 2,000 km above Earth), medium-Earth orbit (approximately 2,000 to 35,500 km above Earth),
and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting at 35,786 km are at
an altitude at which their orbital speed matches the planet's rotation, and are in what is

called geosynchronous orbit (GSO). In addition, a satellite in GSO directly over the equator
will have a geostationary orbit. A geostationary orbit enables a satellite to maintain its
position directly over the same place on Earth’s surface.Low-Earth orbit is a commonly used
orbit since satellites can follow several orbital tracks around the planet. Polar-orbiting
satellites, for example, are inclined nearly 90 degrees to the equatorial plane and travel

from pole to pole as Earth rotates. This enables sensors aboard the satellite to acquire data
for the entire globe rapidly, including the polar regions. Many polar-orbiting satellites
are considered Sun-synchronous, meaning that the satellite passes over the same location at
the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting satellite
is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring. Water budgets for individual watersheds can be estimated
using remote sensing data for precipitation, evapotranspiration, and runoff.Find and use NASA

Earth science data fully, openly, and without restrictions.Recognizing the connections between
interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring

of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)

Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's

rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial

plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early

September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September

4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat

8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,

corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near

Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters

(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can

send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential

downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence Water budgets for individual watersheds can be estimated using remote
sensing data for precipitation, evapotranspiration, and runoff.Find and use NASA Earth science
data fully, openly, and without restrictions.Recognizing the connections between interdependent
Earth systems is critical for understanding the world in which we live.The atmosphere is a

gaseous envelope surrounding and protecting our planet from the intense radiation of the Sun
and serves as a key interface between the terrestrial and ocean cycles.The biosphere encompasses
all life on Earth and extends from root systems to mountaintops and all depths of the ocean.
It is critical for maintaining species diversity, regulating climate, and providing numerous
ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including glaciers

and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays a critical
role in regulating climate and sea levels.The human dimensions discipline includes ways humans
interact with the environment and how these interactions impact Earth’s systems. It also explores
the vulnerability of human communities to natural disasters and hazards.The land surface discipline
includes research into areas such as shrinking forests, warming land, and eroding soils. NASA

data provide key information on land surface parameters and the ecological state of our planet.This
vast, critical reservoir supports a diversity of life and helps regulate Earth’s climate.Processes
occurring deep within Earth constantly are shaping landforms. Although originating from below
the surface, these processes can be analyzed from ground, air, or space-based measurements.The
Sun influences a variety of physical and chemical processes in Earth’s atmosphere. NASA continually

monitors solar radiation and its effect on the planet.The terrestrial hydrosphere includes
water on the land surface and underground in the form of lakes, rivers, and groundwater along
with total water storage.Whether you are a scientist, an educator, a student, or are just
interested in learning more about NASA’s Earth science data and how to use them, we have the
resources to help. Get information and guides to help you find and use NASA Earth science

data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring
of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote

sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)
Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are

low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's
rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables

a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial
plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting

satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency

Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this

is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth

on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged

particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave

radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through

the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,

for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just

as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour

of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the

intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol

properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere

under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor

can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values

(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented

by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a

100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For

example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is

due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution

that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high

spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for

a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation

satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available

fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.

Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36

bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and

2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded

areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource

management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification

algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data

into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide

focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections

between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing

numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The

land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based

measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have

the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed

decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing

Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to

analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development

and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples

(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated

quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition

data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search

is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)

users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides

the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with

satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying

data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the

last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample

requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's

tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize

granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full

Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,

combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology

community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,

access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health

for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization

tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution

data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global

Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted

to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite

image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see

the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original

VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had

a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services

consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read

about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil

Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting

a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution

satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites

that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples

for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results

and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture

Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application

offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for

data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food

insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.

The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS

NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis

options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements

and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER

data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the

USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO

data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can

be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool

enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data

from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options

include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality

such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters

formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based

ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,

vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni

is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,

primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings

through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships

and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which

works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed

by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary

to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth

Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated

towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers

(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the

same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north

of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September

8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord

rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed

to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung

up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The

satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s

cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track

where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.

“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural

Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices

based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the

U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms

of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the

world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of

the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing Water budgets for individual
watersheds can be estimated using remote sensing data for precipitation, evapotranspiration,
and runoff.Find and use NASA Earth science data fully, openly, and without restrictions.Recognizing
the connections between interdependent Earth systems is critical for understanding the world

in which we live.The atmosphere is a gaseous envelope surrounding and protecting our planet
from the intense radiation of the Sun and serves as a key interface between the terrestrial
and ocean cycles.The biosphere encompasses all life on Earth and extends from root systems
to mountaintops and all depths of the ocean. It is critical for maintaining species diversity,
regulating climate, and providing numerous ecosystem functions.The cryosphere encompasses

the frozen parts of Earth, including glaciers and ice sheets, sea ice, and any other frozen
body of water. The cryosphere plays a critical role in regulating climate and sea levels.The
human dimensions discipline includes ways humans interact with the environment and how these
interactions impact Earth’s systems. It also explores the vulnerability of human communities
to natural disasters and hazards.The land surface discipline includes research into areas

such as shrinking forests, warming land, and eroding soils. NASA data provide key information
on land surface parameters and the ecological state of our planet.This vast, critical reservoir
supports a diversity of life and helps regulate Earth’s climate.Processes occurring deep within
Earth constantly are shaping landforms. Although originating from below the surface, these
processes can be analyzed from ground, air, or space-based measurements.The Sun influences

a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on
the land surface and underground in the form of lakes, rivers, and groundwater along with
total water storage.Whether you are a scientist, an educator, a student, or are just interested
in learning more about NASA’s Earth science data and how to use them, we have the resources

to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making
NASA's free and open Earth science data interactive, interoperable, and accessible for research
and societal benefit both today and tomorrow.Remote sensing is the acquiring of information
from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites

and aircraft that detect and record reflected or emitted energy. Remote sensors, which provide
a global perspective and a wealth of data about Earth systems, enable data-informed decision
making based on the current and future state of our planet.For more information, check out
NASA's Interagency Implementation and Advanced Concepts Team (IMPACT) Tech Talk: From Pixels
to Products: An Overview of Satellite Remote Sensing.Satellites can be placed in several types

of orbits around Earth. The three common classes of orbits are low-Earth orbit (approximately
160 to 2,000 km above Earth), medium-Earth orbit (approximately 2,000 to 35,500 km above Earth),
and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting at 35,786 km are at
an altitude at which their orbital speed matches the planet's rotation, and are in what is
called geosynchronous orbit (GSO). In addition, a satellite in GSO directly over the equator

will have a geostationary orbit. A geostationary orbit enables a satellite to maintain its
position directly over the same place on Earth’s surface.Low-Earth orbit is a commonly used
orbit since satellites can follow several orbital tracks around the planet. Polar-orbiting
satellites, for example, are inclined nearly 90 degrees to the equatorial plane and travel
from pole to pole as Earth rotates. This enables sensors aboard the satellite to acquire data

for the entire globe rapidly, including the polar regions. Many polar-orbiting satellites
are considered Sun-synchronous, meaning that the satellite passes over the same location at
the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting satellite
is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead

cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on

the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can

be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's

Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have

a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,

like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface

and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things

on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For

more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive

sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These

sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band

of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific

information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,

an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined

by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image

below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The

narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner

of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,

the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16

days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to

make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data

are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data

are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health

and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band

1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat

8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful

for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once

data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification

uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other

GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based

research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use

NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most

is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?

Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications

topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on

the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For

more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.

Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization

tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution

data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.

Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International

Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows

FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early

Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output

options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)

distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse

more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,

and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples

for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata

Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced

and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers

geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network

Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator

consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data

found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System

(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System

(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land

surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.

There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate

new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,

Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access

the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's

Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also

facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude

or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization

application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes

geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types

of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS

Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish

to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop

planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data

files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The

Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and

forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS

NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full

Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration

(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and

solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.

These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,

airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,

view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5

cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,

elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"

link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season

crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science

resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out

the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop

Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform

application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide

Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and

Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states

in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV

data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution

data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options

include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,

analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct

application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key

elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.

The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets

are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division

through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain

on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s

port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The

image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,

north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image

below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat

data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods

out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land

Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color

image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs

and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers

working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind

and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,

Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms

don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations

able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce

abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average

elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International

Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama

Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes

supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a

means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in

June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13

meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat

data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds

of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of

the United States. Image of the Day Land Life Water Drought Water budgets for individual watersheds
can be estimated using remote sensing data for precipitation, evapotranspiration, and runoff.Find
and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation

of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays

a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological

state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere

includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate

with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring
of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable

data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)
Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately

2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's
rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth

orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial
plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same

location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous

low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth

orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each

observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These

waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation

is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.

Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The

ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.

Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use

the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are

designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud

cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles

of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There

are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values

are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging

Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution

is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information

in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal

resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and

Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable

features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal

resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led

Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical

Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,

bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined

to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,

such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization

Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.

There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.

The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors

measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.

Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The

atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including

glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,

and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.

NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science

data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe

weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote

Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.

NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify

critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from

a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each

sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make

improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant

data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,

KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System

(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land

surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.

There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate

new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly

1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based

query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,

which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)

offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated

quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available

through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF

and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis

options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application

that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as

well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support

tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different

EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition

data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor

Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides

early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply

data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:

NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers

are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting

and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users

not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize

and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active

Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and

Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required

to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers

plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate

ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation

and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables

near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses

publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access

the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's

Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also

facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude

or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor

is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,

and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing

nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region

and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,

Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,

and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni

is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,

primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.

Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,

and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct

application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly

intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding

of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are

many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new

datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series

of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor

these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality

of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of

People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources

in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth

observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.

The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair

of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields

in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages

along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding

along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for

September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled

storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,

and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine

the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms

are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated

with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common

nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers

to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of

microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff

from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after

the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has

very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much

larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus

of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance

on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing

backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began

reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.

At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image

of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received

a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled

wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain
and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the

atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived
from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature

of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent
of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much

as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,
2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s

Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause
water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,

such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite
captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain

over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.
“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter

storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some
research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but

grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global
Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,

and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,
causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching

the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and
west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing Water

budgets for individual watersheds can be estimated using remote sensing data for precipitation,
evapotranspiration, and runoff.Find and use NASA Earth science data fully, openly, and without
restrictions.Recognizing the connections between interdependent Earth systems is critical
for understanding the world in which we live.The atmosphere is a gaseous envelope surrounding
and protecting our planet from the intense radiation of the Sun and serves as a key interface

between the terrestrial and ocean cycles.The biosphere encompasses all life on Earth and extends
from root systems to mountaintops and all depths of the ocean. It is critical for maintaining
species diversity, regulating climate, and providing numerous ecosystem functions.The cryosphere
encompasses the frozen parts of Earth, including glaciers and ice sheets, sea ice, and any
other frozen body of water. The cryosphere plays a critical role in regulating climate and

sea levels.The human dimensions discipline includes ways humans interact with the environment
and how these interactions impact Earth’s systems. It also explores the vulnerability of human
communities to natural disasters and hazards.The land surface discipline includes research
into areas such as shrinking forests, warming land, and eroding soils. NASA data provide key
information on land surface parameters and the ecological state of our planet.This vast, critical

reservoir supports a diversity of life and helps regulate Earth’s climate.Processes occurring
deep within Earth constantly are shaping landforms. Although originating from below the surface,
these processes can be analyzed from ground, air, or space-based measurements.The Sun influences
a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on

the land surface and underground in the form of lakes, rivers, and groundwater along with
total water storage.Whether you are a scientist, an educator, a student, or are just interested
in learning more about NASA’s Earth science data and how to use them, we have the resources
to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making

NASA's free and open Earth science data interactive, interoperable, and accessible for research
and societal benefit both today and tomorrow.Remote sensing is the acquiring of information
from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites
and aircraft that detect and record reflected or emitted energy. Remote sensors, which provide
a global perspective and a wealth of data about Earth systems, enable data-informed decision

making based on the current and future state of our planet.For more information, check out
NASA's Interagency Implementation and Advanced Concepts Team (IMPACT) Tech Talk: From Pixels
to Products: An Overview of Satellite Remote Sensing.Satellites can be placed in several types
of orbits around Earth. The three common classes of orbits are low-Earth orbit (approximately
160 to 2,000 km above Earth), medium-Earth orbit (approximately 2,000 to 35,500 km above Earth),

and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting at 35,786 km are at
an altitude at which their orbital speed matches the planet's rotation, and are in what is
called geosynchronous orbit (GSO). In addition, a satellite in GSO directly over the equator
will have a geostationary orbit. A geostationary orbit enables a satellite to maintain its
position directly over the same place on Earth’s surface.Low-Earth orbit is a commonly used

orbit since satellites can follow several orbital tracks around the planet. Polar-orbiting
satellites, for example, are inclined nearly 90 degrees to the equatorial plane and travel
from pole to pole as Earth rotates. This enables sensors aboard the satellite to acquire data
for the entire globe rapidly, including the polar regions. Many polar-orbiting satellites
are considered Sun-synchronous, meaning that the satellite passes over the same location at

the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting satellite
is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous

low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth

orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each

observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These

waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation

is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.

Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The

ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.

Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use

the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are

designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud

cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles

of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There

are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values

are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging

Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution

is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information

in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal

resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and

Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable

features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal

resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led

Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical

Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,

bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined

to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,

such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization

Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.

There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.

The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors

measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.

Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The

atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including

glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,

and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.

NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science

data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe

weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote

Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.

NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify

critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from

a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each

sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make

improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant

data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,

KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System

(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land

surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.

There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate

new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly

1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based

query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,

which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)

offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated

quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available

through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF

and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis

options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application

that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as

well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support

tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different

EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition

data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor

Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides

early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply

data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:

NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers

are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting

and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users

not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize

and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active

Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and

Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required

to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers

plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate

ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation

and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables

near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses

publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access

the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's

Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also

facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude

or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor

is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,

and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing

nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region

and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,

Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,

and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni

is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,

primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.

Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,

and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct

application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly

intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding

of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are

many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new

datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series

of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor

these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality

of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of

People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources

in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth

observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.

The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair

of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields

in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages

along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding

along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for

September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled

storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,

and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine

the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms

are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated

with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common

nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers

to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of

microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff

from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after

the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has

very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much

larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus

of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance

on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing

backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began

reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.

At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image

of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received

a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled

wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain
and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the

atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived
from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature

of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent
of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much

as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,
2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s

Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause
water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,

such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite
captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain

over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.
“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter

storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some
research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but

grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global
Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,

and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,
causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching

the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and
west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August

21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained
by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things

that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).
“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were

more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has
been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale

Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures

since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more
heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas

in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects
on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed

by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño
in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly

when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious
effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific

represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for
a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense

events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine
heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing

El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters
from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter

and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several
different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the

Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.
Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image

of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other
month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near

coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that
lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water Water budgets for individual watersheds
can be estimated using remote sensing data for precipitation, evapotranspiration, and runoff.Find

and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring

of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)

Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's

rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial

plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early

September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September

4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat

8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,

corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near

Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters

(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can

send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential

downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer

of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores

solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking

water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between

2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where

fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might

pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.

“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water

Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the

“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased

nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.

Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free

view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,

from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops

off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for

the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only

the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river

and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly

affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain

and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived

from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent

of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,

2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause

water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite

captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.

“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some

research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global

Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,

causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and

west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained

by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).

“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has

been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well

as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more

heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects

on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño

in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious

effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for

a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine

heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters

from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several

different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.

Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other

month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that

lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.

One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August

19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite

data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly

leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,

the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated

in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the

Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of

clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms Water budgets for individual watersheds can
be estimated using remote sensing data for precipitation, evapotranspiration, and runoff.Find

and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring

of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)

Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's

rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial

plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early

September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September

4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat

8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,

corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near

Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters

(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can

send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential

downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer

of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores

solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking

water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between

2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where

fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might

pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.

“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water

Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the

“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased

nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.

Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free

view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,

from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops

off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for

the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only

the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river

and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly

affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain

and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived

from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent

of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,

2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause

water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite

captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.

“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some

research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global

Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,

causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and

west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained

by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).

“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has

been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well

as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more

heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects

on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño

in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious

effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for

a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine

heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters

from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several

different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.

Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other

month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that

lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.

One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August

19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite

data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly

leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,

the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated

in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the

Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of

clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green
water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which

are likely comprised of both phytoplankton and sediment—stood out in this image, acquired
by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this
image. But coastal areas were cloud-free, exposing water that likely contained flourishing
populations of phytoplankton—floating plant-like organisms that are the foundation of the

aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer
as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown
that a significant amount of nutrients are supplied by the circulation and upwelling that
occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf

off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running
off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton
armored with calcium carbonate plates—tend to make the water appear more milky-blue and might
be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,

Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,
including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren
Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite
System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton

and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August
2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.Skirting
the coastline of Mozambique, these 32 small islands are home to a diversity of corals and

sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese
pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic
Sea. Image of the Day Land Image of the Day Land Unique Imagery Water budgets for individual
watersheds can be estimated using remote sensing data for precipitation, evapotranspiration,

and runoff.Find and use NASA Earth science data fully, openly, and without restrictions.Recognizing
the connections between interdependent Earth systems is critical for understanding the world
in which we live.The atmosphere is a gaseous envelope surrounding and protecting our planet
from the intense radiation of the Sun and serves as a key interface between the terrestrial
and ocean cycles.The biosphere encompasses all life on Earth and extends from root systems

to mountaintops and all depths of the ocean. It is critical for maintaining species diversity,
regulating climate, and providing numerous ecosystem functions.The cryosphere encompasses
the frozen parts of Earth, including glaciers and ice sheets, sea ice, and any other frozen
body of water. The cryosphere plays a critical role in regulating climate and sea levels.The
human dimensions discipline includes ways humans interact with the environment and how these

interactions impact Earth’s systems. It also explores the vulnerability of human communities
to natural disasters and hazards.The land surface discipline includes research into areas
such as shrinking forests, warming land, and eroding soils. NASA data provide key information
on land surface parameters and the ecological state of our planet.This vast, critical reservoir
supports a diversity of life and helps regulate Earth’s climate.Processes occurring deep within

Earth constantly are shaping landforms. Although originating from below the surface, these
processes can be analyzed from ground, air, or space-based measurements.The Sun influences
a variety of physical and chemical processes in Earth’s atmosphere. NASA continually monitors
solar radiation and its effect on the planet.The terrestrial hydrosphere includes water on
the land surface and underground in the form of lakes, rivers, and groundwater along with

total water storage.Whether you are a scientist, an educator, a student, or are just interested
in learning more about NASA’s Earth science data and how to use them, we have the resources
to help. Get information and guides to help you find and use NASA Earth science data, services,
and tools.We provide a variety of ways for Earth scientists to collaborate with NASA.Making
NASA's free and open Earth science data interactive, interoperable, and accessible for research

and societal benefit both today and tomorrow.Remote sensing is the acquiring of information
from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites
and aircraft that detect and record reflected or emitted energy. Remote sensors, which provide
a global perspective and a wealth of data about Earth systems, enable data-informed decision
making based on the current and future state of our planet.For more information, check out

NASA's Interagency Implementation and Advanced Concepts Team (IMPACT) Tech Talk: From Pixels
to Products: An Overview of Satellite Remote Sensing.Satellites can be placed in several types
of orbits around Earth. The three common classes of orbits are low-Earth orbit (approximately
160 to 2,000 km above Earth), medium-Earth orbit (approximately 2,000 to 35,500 km above Earth),
and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting at 35,786 km are at

an altitude at which their orbital speed matches the planet's rotation, and are in what is
called geosynchronous orbit (GSO). In addition, a satellite in GSO directly over the equator
will have a geostationary orbit. A geostationary orbit enables a satellite to maintain its
position directly over the same place on Earth’s surface.Low-Earth orbit is a commonly used
orbit since satellites can follow several orbital tracks around the planet. Polar-orbiting

satellites, for example, are inclined nearly 90 degrees to the equatorial plane and travel
from pole to pole as Earth rotates. This enables sensors aboard the satellite to acquire data
for the entire globe rapidly, including the polar regions. Many polar-orbiting satellites
are considered Sun-synchronous, meaning that the satellite passes over the same location at
the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting satellite

is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south

latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite

system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary

Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;

a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes

the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many

weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the

rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different

rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring

energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic

radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is

frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among

others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and

temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest

differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x

1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower

bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At

this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same

observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth

as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution

(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a

high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most

have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available

to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal

resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery

of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating

a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.

For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article

How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group

like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or

other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from

NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation

of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays

a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological

state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere

includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate

with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of

selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned

in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis

that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are

updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using

spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about

data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset

to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted

to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite

image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see

the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought

Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer

is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.

Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,

and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of

federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each

sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,

search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the

bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting

data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that

your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable

applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators

bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different

climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make

improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,

soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International

Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows

FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early

Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output

options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,

and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology

and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.

These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,

airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,

view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5

cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas

such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access

and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations

with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of

rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument

in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for

and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users

can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.

The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple

meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.

This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in

areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services

consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read

about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil

Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting

a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief

allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories

through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The

Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots

help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA

Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved

decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are

many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new

datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop

computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through

custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform

that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by

policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.

ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction

Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and

Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water

management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related

efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.

Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,

including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,

2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,

also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in

Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for

about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According

to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer

(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The

melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive

flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,

which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria

(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including

a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby

St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain

is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,

upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a

science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the

northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby

lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients

derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile

some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to

14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the

system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time

of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)

permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,

reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of

the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are

directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some

relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain
and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column

of the atmosphere if all of the water vapor were condensed into liquid. The image was derived
from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor

from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent
of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets

reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,
2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced

the incoming river of moisture upward, where lower air pressure and cooler temperatures cause
water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear

brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite
captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago

in a year.The El Niño developing in the Pacific may be affecting how these events play out.
“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged

in the 1990s and has become a topic of growing interest to researchers in recent years. Some
research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA

Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global
Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land

Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,
causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image

of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and
west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average

sea surface temperatures had surpassed the highest levels seen in a key data record maintained
by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to

record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).
“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions

of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has
been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements

of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest

waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more
heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such

as weather and wind patterns or the distribution of dust and aerosols—have short-term effects
on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that

helped push sea surface temperatures into record territory in 2023 was the evolving El Niño
in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started

to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious
effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent

anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for
a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects

the heat in the equatorial Pacific to have more staying power than many of the other marine
heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways

that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters
from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at

NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several
different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory

image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.
Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in

July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other
month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote

Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that
lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,

Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.
One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the

storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August
19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the

Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite
data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113

kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly
leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six

months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,
the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon

and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated
in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image

of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the
Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly

like a hurricane without most of its center, over the California coast. Isolated areas of
clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green

water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which
are likely comprised of both phytoplankton and sediment—stood out in this image, acquired
by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this
image. But coastal areas were cloud-free, exposing water that likely contained flourishing

populations of phytoplankton—floating plant-like organisms that are the foundation of the
aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer
as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown
that a significant amount of nutrients are supplied by the circulation and upwelling that

occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf
off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running
off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton
armored with calcium carbonate plates—tend to make the water appear more milky-blue and might

be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,
Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,
including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren
Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite

System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton
and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August
2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.Skirting

the coastline of Mozambique, these 32 small islands are home to a diversity of corals and
sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese
pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic
Sea. Image of the Day Land Image of the Day Land Unique Imagery At the base of the ocean food

web are single-celled algae and other plant-like organisms known as phytoplankton. Like plants
on land, phytoplankton use chlorophyll and other light-harvesting pigments to carry out photosynthesis,
absorbing atmospheric carbon dioxide to produce sugars for fuel. Chlorophyll in the water
changes the way it reflects and absorbs sunlight, allowing scientists to map the amount and
location of phytoplankton. These measurements give scientists valuable insights into the health

of the ocean environment, and help scientists study the ocean carbon cycle.These chlorophyll
maps show milligrams of chlorophyll per cubic meter of seawater each month. Places where chlorophyll
amounts were very low, indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were growing, are dark green.
The observations come from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's

Aqua satellite. Land is dark gray, and places where MODIS could not collect data because of
sea ice, polar darkness, or clouds are light gray.The highest chlorophyll concentrations,
where tiny surface-dwelling ocean plants are thriving, are in cold polar waters or in places
where ocean currents bring cold water to the surface, such as around the equator and along
the shores of continents. It is not the cold water itself that stimulates the phytoplankton.

Instead, the cool temperatures are often a sign that the water has welled up to the surface
from deeper in the ocean, carrying nutrients that have built up over time. In polar waters,
nutrients accumulate in surface waters during the dark winter months when plants can't grow.
When sunlight returns in the spring and summer, the plants flourish in high concentrations.A
band of cool, plant-rich waters circles the globe at the Equator, with the strongest signal

in the Atlantic Ocean and the open waters of the Pacific Ocean. This zone of enhanced phytoplankton
growth comes from the frequent upwelling of cooler, deeper water as a result of the dominant
easterly trade winds blowing across the ocean surface. In many coastal areas, the rising slope
of the sea floor pushes cold water from the lowest layers of the ocean to the surface. The
rising, or upwelling water carries iron and other nutrients from the ocean floor. Cold coastal

upwelling and subsequent phytoplankton growth are most evident along the west coasts of North
and South America and southern Africa.View, download, or analyze more of these data from NASA
Earth Observations (NEO): Chlorophyll Life Water Water budgets for individual watersheds can
be estimated using remote sensing data for precipitation, evapotranspiration, and runoff.Find
and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections

between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing

numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The

land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based

measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have

the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring
of information from a distance. NASA observes Earth and other planetary bodies via remote

sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)
Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can

be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's
rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in

GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial
plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite

to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead

cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on

the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can

be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's

Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have

a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,

like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface

and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things

on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For

more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive

sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These

sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band

of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific

information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,

an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined

by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image

below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The

narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner

of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,

the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16

days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to

make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data

are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data

are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health

and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band

1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat

8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful

for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once

data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification

uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other

GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based

research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use

NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most

is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?

Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications

topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on

the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For

more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.

Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization

tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution

data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.

Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International

Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows

FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early

Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output

options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)

distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse

more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,

and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples

for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata

Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced

and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers

geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network

Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator

consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data

found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System

(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System

(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land

surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.

There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate

new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,

Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access

the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's

Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also

facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude

or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization

application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes

geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types

of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS

Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish

to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop

planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data

files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The

Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and

forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS

NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full

Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration

(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and

solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.

These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,

airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,

view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5

cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,

elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"

link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season

crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science

resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out

the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop

Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform

application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide

Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and

Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states

in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV

data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution

data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service

(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options

include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,

analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct

application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key

elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.

The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets

are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division

through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain

on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s

port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The

image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,

north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image

below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat

data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods

out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land

Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color

image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs

and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers

working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind

and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,

Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms

don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations

able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce

abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average

elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International

Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama

Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes

supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a

means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in

June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13

meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat

data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds

of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of

the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain
and snow to the region. However, too much rain fell too quickly in some areas, prompting floods

and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived
from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical

processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent
of the annual precipitation, most of it in the winter rainy season (June to September).El

Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,
2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.

“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause
water vapor to more easily condense into rain droplets on the windward side of mountains.

This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite
captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific

Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.
“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere

is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some
research suggests that climate change may be causing atmospheric rivers to produce more rain

and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global
Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.

Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,
causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric

river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and
west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique

Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained
by NOAA. Months later, they remain at record levels, with global sea surface temperatures

0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).
“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming

that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has
been the case for weeks, large patches of warm water were also present in the Northwest Pacific

near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects

the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more
heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the

director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects
on sea surface temperatures in certain regions, but they generally have a minor effect on

the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño
in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and

intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious
effects on marine life and weather in Europe in the coming months. But it’s the Pacific that

has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for
a given time of year)—have occurred recently in several areas. One NOAA analysis showed that

48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine
heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral

and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters
from NOAA say that there is a greater than 95 percent chance that El Niño conditions will

persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several
different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical

Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.
Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by

Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other
month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon

emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that
lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when

surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.
One person was killed by the floodwater, according to officials. Hilary weakened to a tropical

storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August
19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern

California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite
data, local rainfall rates may be significantly higher when measured from the ground. August

20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly
leaving 40,000 residents without power. Death Valley National Park closed due to flooding,

and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,
the major highway in the region. August is typically a dry month in Southern California, but

the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated
in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,

using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the
Day:The hurricane season in the Pacific runs from June through November, though the storms

can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of
clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms

Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green
water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which
are likely comprised of both phytoplankton and sediment—stood out in this image, acquired

by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this
image. But coastal areas were cloud-free, exposing water that likely contained flourishing
populations of phytoplankton—floating plant-like organisms that are the foundation of the
aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer

as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown
that a significant amount of nutrients are supplied by the circulation and upwelling that
occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf
off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running

off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton
armored with calcium carbonate plates—tend to make the water appear more milky-blue and might
be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,
Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,

including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren
Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite
System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton
and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August

2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.Skirting
the coastline of Mozambique, these 32 small islands are home to a diversity of corals and
sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese

pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic
Sea. Image of the Day Land Image of the Day Land Unique Imagery At the base of the ocean food
web are single-celled algae and other plant-like organisms known as phytoplankton. Like plants
on land, phytoplankton use chlorophyll and other light-harvesting pigments to carry out photosynthesis,

absorbing atmospheric carbon dioxide to produce sugars for fuel. Chlorophyll in the water
changes the way it reflects and absorbs sunlight, allowing scientists to map the amount and
location of phytoplankton. These measurements give scientists valuable insights into the health
of the ocean environment, and help scientists study the ocean carbon cycle.These chlorophyll
maps show milligrams of chlorophyll per cubic meter of seawater each month. Places where chlorophyll

amounts were very low, indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were growing, are dark green.
The observations come from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's
Aqua satellite. Land is dark gray, and places where MODIS could not collect data because of
sea ice, polar darkness, or clouds are light gray.The highest chlorophyll concentrations,

where tiny surface-dwelling ocean plants are thriving, are in cold polar waters or in places
where ocean currents bring cold water to the surface, such as around the equator and along
the shores of continents. It is not the cold water itself that stimulates the phytoplankton.
Instead, the cool temperatures are often a sign that the water has welled up to the surface
from deeper in the ocean, carrying nutrients that have built up over time. In polar waters,

nutrients accumulate in surface waters during the dark winter months when plants can't grow.
When sunlight returns in the spring and summer, the plants flourish in high concentrations.A
band of cool, plant-rich waters circles the globe at the Equator, with the strongest signal
in the Atlantic Ocean and the open waters of the Pacific Ocean. This zone of enhanced phytoplankton
growth comes from the frequent upwelling of cooler, deeper water as a result of the dominant

easterly trade winds blowing across the ocean surface. In many coastal areas, the rising slope
of the sea floor pushes cold water from the lowest layers of the ocean to the surface. The
rising, or upwelling water carries iron and other nutrients from the ocean floor. Cold coastal
upwelling and subsequent phytoplankton growth are most evident along the west coasts of North
and South America and southern Africa.View, download, or analyze more of these data from NASA

Earth Observations (NEO): Chlorophyll Life Water September 12, 2023JPEGOn September 12, 2023,
Hurricane Lee continued its slow west-northwest trajectory across the Atlantic Ocean. The
Geostationary Operational Environmental Satellite 16 (GOES-16) acquired this image of the
major storm at approximately 1 p.m. Eastern Time (17:00 UTC) as it advanced toward the southeastern
United States. The satellite is operated by the National Oceanic and Atmospheric Administration

(NOAA); NASA helps develop and launch the GOES series of satellites. Around this time, the
center of the hurricane was located about 500 miles (800 kilometers) south of Bermuda and
moving at 6 miles (9 kilometers) per hour. Sustained winds were measured at 115 miles (185
kilometers) per hour, making it a category 3 storm on the Saffir-Simpson hurricane wind scale.On
its path across the ocean to this point, the hurricane fluctuated dramatically in strength,

as it underwent one of the most extreme periods of rapid intensification for a North Atlantic
storm in the past 40 years. In the 24 hours ending at 2 a.m. Eastern Time (06:00 UTC) on September
8, Lee’s winds increased from 80 to 165 miles per hour (130 to 265 kilometers per hour), escalating
it to category 5 status. Only Hurricane Felix in 2007 and Hurricane Wilma in 2005 intensified
more over a 24-hour period. Following this ramp-up, moderate to strong wind shear disrupted

the storm’s circulation and weakened it to a category 2. September 10, 2023JPEGThat would
not be the last momentum swing, however. On September 10, Hurricane Lee began to regain strength
as wind shear abated and it passed over very warm waters. The map above shows sea surface
temperatures on from that day based on data from the Multiscale Ultrahigh Resolution Sea Surface
Temperature (MUR SST) project, a NASA Jet Propulsion Laboratory effort that blends measurements

of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. High sea surface temperatures are among the conditions favorable
to hurricane intensification. And 2023 has been a banner year for warm oceans. Decades of
gradual warming due to climate change, along with El Niño conditions in the Pacific Ocean,
helped drive global sea surface temperatures into record territory for several months in the

summer. Meteorologists generally agree that sea surface temperatures above 27.8 degrees Celsius
(82 degrees Fahrenheit) will sustain and intensify hurricanes, cyclones, and typhoons. Surface
waters above that threshold are shown in red to black on the map. Forecast models indicate
that a weather pattern over the eastern U.S. will redirect Lee to the north. The storm is
expected to expand in size and weaken as it moves over cooler waters recently churned up by

hurricanes Franklin and Idalia. The storm will likely pass west of Bermuda, which is under
a tropical storm watch, and potentially make landfall over the northeastern U.S. or Nova Scotia
as a much weaker storm. NASA Earth Observatory images by Lauren Dauphin, using GOES 16 imagery
courtesy of NOAA and the National Environmental Satellite, Data, and Information Service (NESDIS)
and data from the Multiscale Ultrahigh Resolution (MUR) project. Story by Lindsey Doermann.View

this area in EO ExplorerThe major storm fluctuated in intensity as it approached the U.S.
East Coast.Image of the Day for September 13, 2023 Image of the Day Land Water Severe Storms
View more Images of the Day:Hurricane season in the basin runs from June 1 to November 30.Acquired
August 23, 2009, this true-color image shows Hurricane Bill missing the U.S., apparently headed
northward toward Canada. Atmosphere Water Severe Storms The first hurricane of the Atlantic

season made a series of landfalls and dropped abundant rain from the Caribbean to the U.S.
East Coast. Heat Water Severe Storms Human Presence The SeaWiFS instrument captured the data
for this composite view of an August 2000 hurricane while it was near Bermuda. Image of the
Day Atmosphere Though it has weakened since reaching category 5 strength, the hurricane is
still bringing heavy rain and strong winds to the northeast Atlantic. Image of the Day Floods

Severe Storms Remote Sensing Water budgets for individual watersheds can be estimated using
remote sensing data for precipitation, evapotranspiration, and runoff.Find and use NASA Earth
science data fully, openly, and without restrictions.Recognizing the connections between interdependent
Earth systems is critical for understanding the world in which we live.The atmosphere is a
gaseous envelope surrounding and protecting our planet from the intense radiation of the Sun

and serves as a key interface between the terrestrial and ocean cycles.The biosphere encompasses
all life on Earth and extends from root systems to mountaintops and all depths of the ocean.
It is critical for maintaining species diversity, regulating climate, and providing numerous
ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including glaciers
and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays a critical

role in regulating climate and sea levels.The human dimensions discipline includes ways humans
interact with the environment and how these interactions impact Earth’s systems. It also explores
the vulnerability of human communities to natural disasters and hazards.The land surface discipline
includes research into areas such as shrinking forests, warming land, and eroding soils. NASA
data provide key information on land surface parameters and the ecological state of our planet.This

vast, critical reservoir supports a diversity of life and helps regulate Earth’s climate.Processes
occurring deep within Earth constantly are shaping landforms. Although originating from below
the surface, these processes can be analyzed from ground, air, or space-based measurements.The
Sun influences a variety of physical and chemical processes in Earth’s atmosphere. NASA continually
monitors solar radiation and its effect on the planet.The terrestrial hydrosphere includes

water on the land surface and underground in the form of lakes, rivers, and groundwater along
with total water storage.Whether you are a scientist, an educator, a student, or are just
interested in learning more about NASA’s Earth science data and how to use them, we have the
resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate

with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring
of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable

data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)
Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately

2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's
rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth

orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial
plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same

location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar
low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous

low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12
hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth

orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary
satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each

observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These

waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,
have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation

is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth
and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.

Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,
is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The

ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For
example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.

Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use

the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive
sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are

designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,
infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud

cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,
altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles

of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and
active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There

are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number
of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values

are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is
necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging

Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500
m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution

is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some
sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information

in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation
types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal

resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and
the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and

Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat
8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable

features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between
observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal

resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote
sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led

Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform
space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical

Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,
they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,

bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band
1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined

to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine
an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,

such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National
Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization

Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color
Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.

There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can
be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.

The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated
into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors

measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated
through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.

Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize
or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The

atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including

glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,

and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.

NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science

data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe

weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides
links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote

Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other
data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.

NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological
(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify

critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season
crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from

a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:
point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each

sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make

improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant

data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and
download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,

KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)
provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System

(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land

surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.

There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate

new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought
relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly

1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products
(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based

query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The
NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,

which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services
(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)

offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,
temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated

quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available

through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit
requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF

and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis

options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed
using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application

that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With
Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as

well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming
Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support

tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides
valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different

EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover
the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition

data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor

Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different
crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides

early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply

data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,
and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:

NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers

are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery
is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting

and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users
to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users

not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users
to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize

and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues
related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active

Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture
and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and

Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and
international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required

to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from
a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers

plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information
System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate

ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access
to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation

and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables

near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,
and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses

publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's
Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access

the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's

Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also

facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude

or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor

is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,

and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for
download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing

nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of
EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region

and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,
and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,

Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see
how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,

and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an
API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging

Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni

is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,

primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,
and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.

Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later
version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,

and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of
restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct

application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation
groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly

intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA
satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding

of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application
or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical

for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are

many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new

datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related
parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series

of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor

these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality
monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality

of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked
global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of

People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved
nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources

in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances
in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth

observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early
September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.

The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September
4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair

of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat
8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields

in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,
corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages

along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near
Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding

along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters
(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for

September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can
send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled

storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential
downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,

and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer
of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine

the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores
solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms

are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking
water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated

with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between
2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common

nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where
fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers

to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might
pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of

microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.
“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff

from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water
Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after

the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the
“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has

very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased
nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much

larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.
Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus

of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free
view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance

on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,
from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing

backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops
off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began

reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for
the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.

At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only
the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image

of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river
and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received

a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly
affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled

wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain
and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the

atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived
from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature

of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent
of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much

as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,
2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s

Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause
water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,

such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite
captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain

over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.
“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter

storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some
research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but

grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global
Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,

and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,
causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching

the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and
west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August

21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained
by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things

that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).
“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were

more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has
been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale

Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures

since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more
heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas

in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects
on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed

by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño
in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly

when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious
effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific

represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for
a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense

events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine
heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing

El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters
from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter

and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several
different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the

Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.
Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image

of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other
month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near

coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that
lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,

pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.
One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,

mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August
19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates

that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite
data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches

(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly
leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern

California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,
the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could

saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated
in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern

California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the
Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired

January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of
clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.

Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green
water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which
are likely comprised of both phytoplankton and sediment—stood out in this image, acquired
by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this

image. But coastal areas were cloud-free, exposing water that likely contained flourishing
populations of phytoplankton—floating plant-like organisms that are the foundation of the
aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer
as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown

that a significant amount of nutrients are supplied by the circulation and upwelling that
occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf
off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running
off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton

armored with calcium carbonate plates—tend to make the water appear more milky-blue and might
be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,
Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,
including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren

Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite
System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton
and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August
2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.

Extreme blooms of certain species can become harmful to marine animals and humans.Skirting
the coastline of Mozambique, these 32 small islands are home to a diversity of corals and
sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese
pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic

Sea. Image of the Day Land Image of the Day Land Unique Imagery At the base of the ocean food
web are single-celled algae and other plant-like organisms known as phytoplankton. Like plants
on land, phytoplankton use chlorophyll and other light-harvesting pigments to carry out photosynthesis,
absorbing atmospheric carbon dioxide to produce sugars for fuel. Chlorophyll in the water
changes the way it reflects and absorbs sunlight, allowing scientists to map the amount and

location of phytoplankton. These measurements give scientists valuable insights into the health
of the ocean environment, and help scientists study the ocean carbon cycle.These chlorophyll
maps show milligrams of chlorophyll per cubic meter of seawater each month. Places where chlorophyll
amounts were very low, indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were growing, are dark green.

The observations come from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's
Aqua satellite. Land is dark gray, and places where MODIS could not collect data because of
sea ice, polar darkness, or clouds are light gray.The highest chlorophyll concentrations,
where tiny surface-dwelling ocean plants are thriving, are in cold polar waters or in places
where ocean currents bring cold water to the surface, such as around the equator and along

the shores of continents. It is not the cold water itself that stimulates the phytoplankton.
Instead, the cool temperatures are often a sign that the water has welled up to the surface
from deeper in the ocean, carrying nutrients that have built up over time. In polar waters,
nutrients accumulate in surface waters during the dark winter months when plants can't grow.
When sunlight returns in the spring and summer, the plants flourish in high concentrations.A

band of cool, plant-rich waters circles the globe at the Equator, with the strongest signal
in the Atlantic Ocean and the open waters of the Pacific Ocean. This zone of enhanced phytoplankton
growth comes from the frequent upwelling of cooler, deeper water as a result of the dominant
easterly trade winds blowing across the ocean surface. In many coastal areas, the rising slope
of the sea floor pushes cold water from the lowest layers of the ocean to the surface. The

rising, or upwelling water carries iron and other nutrients from the ocean floor. Cold coastal
upwelling and subsequent phytoplankton growth are most evident along the west coasts of North
and South America and southern Africa.View, download, or analyze more of these data from NASA
Earth Observations (NEO): Chlorophyll Life Water September 12, 2023JPEGOn September 12, 2023,
Hurricane Lee continued its slow west-northwest trajectory across the Atlantic Ocean. The

Geostationary Operational Environmental Satellite 16 (GOES-16) acquired this image of the
major storm at approximately 1 p.m. Eastern Time (17:00 UTC) as it advanced toward the southeastern
United States. The satellite is operated by the National Oceanic and Atmospheric Administration
(NOAA); NASA helps develop and launch the GOES series of satellites. Around this time, the
center of the hurricane was located about 500 miles (800 kilometers) south of Bermuda and

moving at 6 miles (9 kilometers) per hour. Sustained winds were measured at 115 miles (185
kilometers) per hour, making it a category 3 storm on the Saffir-Simpson hurricane wind scale.On
its path across the ocean to this point, the hurricane fluctuated dramatically in strength,
as it underwent one of the most extreme periods of rapid intensification for a North Atlantic
storm in the past 40 years. In the 24 hours ending at 2 a.m. Eastern Time (06:00 UTC) on September

8, Lee’s winds increased from 80 to 165 miles per hour (130 to 265 kilometers per hour), escalating
it to category 5 status. Only Hurricane Felix in 2007 and Hurricane Wilma in 2005 intensified
more over a 24-hour period. Following this ramp-up, moderate to strong wind shear disrupted
the storm’s circulation and weakened it to a category 2. September 10, 2023JPEGThat would
not be the last momentum swing, however. On September 10, Hurricane Lee began to regain strength

as wind shear abated and it passed over very warm waters. The map above shows sea surface
temperatures on from that day based on data from the Multiscale Ultrahigh Resolution Sea Surface
Temperature (MUR SST) project, a NASA Jet Propulsion Laboratory effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. High sea surface temperatures are among the conditions favorable

to hurricane intensification. And 2023 has been a banner year for warm oceans. Decades of
gradual warming due to climate change, along with El Niño conditions in the Pacific Ocean,
helped drive global sea surface temperatures into record territory for several months in the
summer. Meteorologists generally agree that sea surface temperatures above 27.8 degrees Celsius
(82 degrees Fahrenheit) will sustain and intensify hurricanes, cyclones, and typhoons. Surface

waters above that threshold are shown in red to black on the map. Forecast models indicate
that a weather pattern over the eastern U.S. will redirect Lee to the north. The storm is
expected to expand in size and weaken as it moves over cooler waters recently churned up by
hurricanes Franklin and Idalia. The storm will likely pass west of Bermuda, which is under
a tropical storm watch, and potentially make landfall over the northeastern U.S. or Nova Scotia

as a much weaker storm. NASA Earth Observatory images by Lauren Dauphin, using GOES 16 imagery
courtesy of NOAA and the National Environmental Satellite, Data, and Information Service (NESDIS)
and data from the Multiscale Ultrahigh Resolution (MUR) project. Story by Lindsey Doermann.View
this area in EO ExplorerThe major storm fluctuated in intensity as it approached the U.S.
East Coast.Image of the Day for September 13, 2023 Image of the Day Land Water Severe Storms

View more Images of the Day:Hurricane season in the basin runs from June 1 to November 30.Acquired
August 23, 2009, this true-color image shows Hurricane Bill missing the U.S., apparently headed
northward toward Canada. Atmosphere Water Severe Storms The first hurricane of the Atlantic
season made a series of landfalls and dropped abundant rain from the Caribbean to the U.S.
East Coast. Heat Water Severe Storms Human Presence The SeaWiFS instrument captured the data

for this composite view of an August 2000 hurricane while it was near Bermuda. Image of the
Day Atmosphere Though it has weakened since reaching category 5 strength, the hurricane is
still bringing heavy rain and strong winds to the northeast Atlantic. Image of the Day Floods
Severe Storms Remote Sensing September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 7, 2023September
13, 2023September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 13, 2023JPEGOn September 10,

2023, a low-pressure storm brought heavy rains to northeastern Libya, causing deadly flooding
and devastation in cities along the Mediterranean coast. On the coast of Libya’s Cyrenaica
region, Al Bayda recorded 414 millimeters (16 inches) of rain in one day. Nearby, the port
city of Derna received more than 100 millimeters (4 inches) over the course of the storm—far
exceeding the city’s average monthly rainfall for September of less than 1.5 millimeters (0.1

inches). Derna lies at the end of a long, narrow valley, called a wadi, which is dry for most
of the year. Floods triggered two dams along Wadi Derna to collapse, sending floodwater and
mud to the city. According to news reports, floodwater swept away roads and entire neighborhoods.
The images above show the Cyrenaica region before and after the storm. They are false color,
which makes water (blue) stand out from the surroundings. The image on the right, acquired

on September 13, shows water filling low-lying areas and wadis inland from the coast. The
image on the left shows the same area on September 7. Both images were acquired with the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The flooding and damage
in Derna is difficult to see at this resolution, although sediment flowing into the Mediterranean
is visible in natural color images. In the days prior to making landfall in Libya, the same

low-pressure storm (named Storm Daniel by the Hellenic National Meteorological Service) swamped
parts of Greece, Turkey, and Bulgaria. As the storm approached Libya, it developed characteristics
of a tropical-like cyclone, or “medicane,” with winds measuring around 70 to 80 kilometers
(43 to 50 miles) per hour. September 10, 2023JPEGThe natural-color image above, acquired with
MODIS on NASA’s Terra satellite, shows the storm on September 10 as it made landfall in northeastern

Libya. Only one or two medicanes typically develop in a year, according to NOAA. As of September
13, authorities were still conducting search and rescue operations in the region. Derna was
still largely inaccessible on that day, making it difficult to assess the full impact of the
flood.NASA Earth Observatory images by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE
and GIBS/Worldview. Story by Emily Cassidy.View this area in EO ExplorerA Mediterranean cyclone

contributed to deadly flooding along the country’s coastline.Image of the Day for September
14, 2023 Image of the Day Land Water Floods View more Images of the Day:The melting of frozen
rivers and snowpack, and the heavy rains of late spring and summer, can send rivers out of
their banks.Flash floods in the port city destroyed roads and swept neighborhoods out to sea.
Image of the Day Land Water Floods Human Presence Record rainfall inundated towns and farmland

in the country’s Thessaly region. Image of the Day Water Floods Human Presence Cities and
towns darkened after a cyclone unleashed torrential flooding along the country’s coast. Image
of the Day Human Presence An extratropical cyclone triggered deadly flooding in the state
of Rio Grande do Sul. Image of the Day Water Floods Water budgets for individual watersheds
can be estimated using remote sensing data for precipitation, evapotranspiration, and runoff.Find

and use NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring

of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)

Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's

rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial

plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early

September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September

4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat

8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,

corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near

Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters

(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can

send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential

downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer

of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores

solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking

water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between

2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where

fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might

pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.

“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water

Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the

“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased

nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.

Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free

view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,

from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops

off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for

the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only

the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river

and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly

affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain

and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived

from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent

of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,

2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause

water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite

captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.

“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some

research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global

Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,

causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and

west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained

by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).

“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has

been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well

as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more

heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects

on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño

in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious

effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for

a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine

heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters

from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several

different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.

Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other

month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that

lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.

One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August

19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite

data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly

leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,

the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated

in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the

Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of

clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green
water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which

are likely comprised of both phytoplankton and sediment—stood out in this image, acquired
by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this
image. But coastal areas were cloud-free, exposing water that likely contained flourishing
populations of phytoplankton—floating plant-like organisms that are the foundation of the

aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer
as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown
that a significant amount of nutrients are supplied by the circulation and upwelling that
occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf

off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running
off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton
armored with calcium carbonate plates—tend to make the water appear more milky-blue and might
be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,

Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,
including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren
Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite
System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton

and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August
2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.Skirting
the coastline of Mozambique, these 32 small islands are home to a diversity of corals and

sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese
pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic
Sea. Image of the Day Land Image of the Day Land Unique Imagery At the base of the ocean food
web are single-celled algae and other plant-like organisms known as phytoplankton. Like plants

on land, phytoplankton use chlorophyll and other light-harvesting pigments to carry out photosynthesis,
absorbing atmospheric carbon dioxide to produce sugars for fuel. Chlorophyll in the water
changes the way it reflects and absorbs sunlight, allowing scientists to map the amount and
location of phytoplankton. These measurements give scientists valuable insights into the health
of the ocean environment, and help scientists study the ocean carbon cycle.These chlorophyll

maps show milligrams of chlorophyll per cubic meter of seawater each month. Places where chlorophyll
amounts were very low, indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were growing, are dark green.
The observations come from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's
Aqua satellite. Land is dark gray, and places where MODIS could not collect data because of

sea ice, polar darkness, or clouds are light gray.The highest chlorophyll concentrations,
where tiny surface-dwelling ocean plants are thriving, are in cold polar waters or in places
where ocean currents bring cold water to the surface, such as around the equator and along
the shores of continents. It is not the cold water itself that stimulates the phytoplankton.
Instead, the cool temperatures are often a sign that the water has welled up to the surface

from deeper in the ocean, carrying nutrients that have built up over time. In polar waters,
nutrients accumulate in surface waters during the dark winter months when plants can't grow.
When sunlight returns in the spring and summer, the plants flourish in high concentrations.A
band of cool, plant-rich waters circles the globe at the Equator, with the strongest signal
in the Atlantic Ocean and the open waters of the Pacific Ocean. This zone of enhanced phytoplankton

growth comes from the frequent upwelling of cooler, deeper water as a result of the dominant
easterly trade winds blowing across the ocean surface. In many coastal areas, the rising slope
of the sea floor pushes cold water from the lowest layers of the ocean to the surface. The
rising, or upwelling water carries iron and other nutrients from the ocean floor. Cold coastal
upwelling and subsequent phytoplankton growth are most evident along the west coasts of North

and South America and southern Africa.View, download, or analyze more of these data from NASA
Earth Observations (NEO): Chlorophyll Life Water September 12, 2023JPEGOn September 12, 2023,
Hurricane Lee continued its slow west-northwest trajectory across the Atlantic Ocean. The
Geostationary Operational Environmental Satellite 16 (GOES-16) acquired this image of the
major storm at approximately 1 p.m. Eastern Time (17:00 UTC) as it advanced toward the southeastern

United States. The satellite is operated by the National Oceanic and Atmospheric Administration
(NOAA); NASA helps develop and launch the GOES series of satellites. Around this time, the
center of the hurricane was located about 500 miles (800 kilometers) south of Bermuda and
moving at 6 miles (9 kilometers) per hour. Sustained winds were measured at 115 miles (185
kilometers) per hour, making it a category 3 storm on the Saffir-Simpson hurricane wind scale.On

its path across the ocean to this point, the hurricane fluctuated dramatically in strength,
as it underwent one of the most extreme periods of rapid intensification for a North Atlantic
storm in the past 40 years. In the 24 hours ending at 2 a.m. Eastern Time (06:00 UTC) on September
8, Lee’s winds increased from 80 to 165 miles per hour (130 to 265 kilometers per hour), escalating
it to category 5 status. Only Hurricane Felix in 2007 and Hurricane Wilma in 2005 intensified

more over a 24-hour period. Following this ramp-up, moderate to strong wind shear disrupted
the storm’s circulation and weakened it to a category 2. September 10, 2023JPEGThat would
not be the last momentum swing, however. On September 10, Hurricane Lee began to regain strength
as wind shear abated and it passed over very warm waters. The map above shows sea surface
temperatures on from that day based on data from the Multiscale Ultrahigh Resolution Sea Surface

Temperature (MUR SST) project, a NASA Jet Propulsion Laboratory effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. High sea surface temperatures are among the conditions favorable
to hurricane intensification. And 2023 has been a banner year for warm oceans. Decades of
gradual warming due to climate change, along with El Niño conditions in the Pacific Ocean,

helped drive global sea surface temperatures into record territory for several months in the
summer. Meteorologists generally agree that sea surface temperatures above 27.8 degrees Celsius
(82 degrees Fahrenheit) will sustain and intensify hurricanes, cyclones, and typhoons. Surface
waters above that threshold are shown in red to black on the map. Forecast models indicate
that a weather pattern over the eastern U.S. will redirect Lee to the north. The storm is

expected to expand in size and weaken as it moves over cooler waters recently churned up by
hurricanes Franklin and Idalia. The storm will likely pass west of Bermuda, which is under
a tropical storm watch, and potentially make landfall over the northeastern U.S. or Nova Scotia
as a much weaker storm. NASA Earth Observatory images by Lauren Dauphin, using GOES 16 imagery
courtesy of NOAA and the National Environmental Satellite, Data, and Information Service (NESDIS)

and data from the Multiscale Ultrahigh Resolution (MUR) project. Story by Lindsey Doermann.View
this area in EO ExplorerThe major storm fluctuated in intensity as it approached the U.S.
East Coast.Image of the Day for September 13, 2023 Image of the Day Land Water Severe Storms
View more Images of the Day:Hurricane season in the basin runs from June 1 to November 30.Acquired
August 23, 2009, this true-color image shows Hurricane Bill missing the U.S., apparently headed

northward toward Canada. Atmosphere Water Severe Storms The first hurricane of the Atlantic
season made a series of landfalls and dropped abundant rain from the Caribbean to the U.S.
East Coast. Heat Water Severe Storms Human Presence The SeaWiFS instrument captured the data
for this composite view of an August 2000 hurricane while it was near Bermuda. Image of the
Day Atmosphere Though it has weakened since reaching category 5 strength, the hurricane is

still bringing heavy rain and strong winds to the northeast Atlantic. Image of the Day Floods
Severe Storms Remote Sensing September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 7, 2023September
13, 2023September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 13, 2023JPEGOn September 10,
2023, a low-pressure storm brought heavy rains to northeastern Libya, causing deadly flooding
and devastation in cities along the Mediterranean coast. On the coast of Libya’s Cyrenaica

region, Al Bayda recorded 414 millimeters (16 inches) of rain in one day. Nearby, the port
city of Derna received more than 100 millimeters (4 inches) over the course of the storm—far
exceeding the city’s average monthly rainfall for September of less than 1.5 millimeters (0.1
inches). Derna lies at the end of a long, narrow valley, called a wadi, which is dry for most
of the year. Floods triggered two dams along Wadi Derna to collapse, sending floodwater and

mud to the city. According to news reports, floodwater swept away roads and entire neighborhoods.
The images above show the Cyrenaica region before and after the storm. They are false color,
which makes water (blue) stand out from the surroundings. The image on the right, acquired
on September 13, shows water filling low-lying areas and wadis inland from the coast. The
image on the left shows the same area on September 7. Both images were acquired with the Moderate

Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The flooding and damage
in Derna is difficult to see at this resolution, although sediment flowing into the Mediterranean
is visible in natural color images. In the days prior to making landfall in Libya, the same
low-pressure storm (named Storm Daniel by the Hellenic National Meteorological Service) swamped
parts of Greece, Turkey, and Bulgaria. As the storm approached Libya, it developed characteristics

of a tropical-like cyclone, or “medicane,” with winds measuring around 70 to 80 kilometers
(43 to 50 miles) per hour. September 10, 2023JPEGThe natural-color image above, acquired with
MODIS on NASA’s Terra satellite, shows the storm on September 10 as it made landfall in northeastern
Libya. Only one or two medicanes typically develop in a year, according to NOAA. As of September
13, authorities were still conducting search and rescue operations in the region. Derna was

still largely inaccessible on that day, making it difficult to assess the full impact of the
flood.NASA Earth Observatory images by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE
and GIBS/Worldview. Story by Emily Cassidy.View this area in EO ExplorerA Mediterranean cyclone
contributed to deadly flooding along the country’s coastline.Image of the Day for September
14, 2023 Image of the Day Land Water Floods View more Images of the Day:The melting of frozen

rivers and snowpack, and the heavy rains of late spring and summer, can send rivers out of
their banks.Flash floods in the port city destroyed roads and swept neighborhoods out to sea.
Image of the Day Land Water Floods Human Presence Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence Cities and
towns darkened after a cyclone unleashed torrential flooding along the country’s coast. Image

of the Day Human Presence An extratropical cyclone triggered deadly flooding in the state
of Rio Grande do Sul. Image of the Day Water Floods Sea surface temperatures have a large
influence on climate and weather. For example, every 3 to 7 years a wide swath of the Pacific
Ocean along the equator warms by 2 to 3 degrees Celsius. This warming is a hallmark of the
climate pattern El Niño, which changes rainfall patterns around the globe, causing heavy rainfall

in the southern United States and severe drought in Australia, Indonesia, and southern Asia.
On a smaller scale, ocean temperatures influence the development of tropical cyclones (hurricanes
and typhoons), which draw energy from warm ocean waters to form and intensify.These sea surface
temperature maps are based on observations by the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Aqua satellite. The satellite measures the temperature of the top millimeter

of the ocean surface. In this map, the coolest waters appear in blue (approximately -2 degrees
Celsius), and the warmest temperatures appear in pink-yellow (35 degrees Celsius). Landmasses
and the large area of sea ice around Antarctica appear in shades of gray, indicating no data
were collected.The most obvious pattern shown in the time series is the year-round difference
in sea surface temperatures between equatorial regions and the poles. Various warm and cool

currents stand out even in monthly averages of sea surface temperature. A band of warm waters
snakes up the East Coast of the United States and veers across the North Atlantic—the Gulf
Stream.Although short-lived weather events that influence ocean temperature are often washed
out in monthly averages, a few events show up. For example, in December 2003, strong winds
blew southwest from the Gulf of Mexico over Central America toward the Pacific Ocean, driving

surface waters away from the coast, and allowing cold water from deeper in the ocean to well
up to the surface. These winds are a recurring phenomenon in the area in the winter; they
are known as Tehuano winds.View, download, or analyze more of these data from NASA Earth Observations
(NEO): Sea Surface Temperature Heat Water Water budgets for individual watersheds can be estimated
using remote sensing data for precipitation, evapotranspiration, and runoff.Find and use NASA

Earth science data fully, openly, and without restrictions.Recognizing the connections between
interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere
encompasses all life on Earth and extends from root systems to mountaintops and all depths

of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes
ways humans interact with the environment and how these interactions impact Earth’s systems.

It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate
Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although

originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater
along with total water storage.Whether you are a scientist, an educator, a student, or are

just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible
for research and societal benefit both today and tomorrow.Remote sensing is the acquiring

of information from a distance. NASA observes Earth and other planetary bodies via remote
sensors on satellites and aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective and a wealth of data about Earth systems, enable
data-informed decision making based on the current and future state of our planet.For more
information, check out NASA's Interagency Implementation and Advanced Concepts Team (IMPACT)

Tech Talk: From Pixels to Products: An Overview of Satellite Remote Sensing.Satellites can
be placed in several types of orbits around Earth. The three common classes of orbits are
low-Earth orbit (approximately 160 to 2,000 km above Earth), medium-Earth orbit (approximately
2,000 to 35,500 km above Earth), and high-Earth orbit (above 35,500 km above Earth). Satellites
orbiting at 35,786 km are at an altitude at which their orbital speed matches the planet's

rotation, and are in what is called geosynchronous orbit (GSO). In addition, a satellite in
GSO directly over the equator will have a geostationary orbit. A geostationary orbit enables
a satellite to maintain its position directly over the same place on Earth’s surface.Low-Earth
orbit is a commonly used orbit since satellites can follow several orbital tracks around the
planet. Polar-orbiting satellites, for example, are inclined nearly 90 degrees to the equatorial

plane and travel from pole to pole as Earth rotates. This enables sensors aboard the satellite
to acquire data for the entire globe rapidly, including the polar regions. Many polar-orbiting
satellites are considered Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example of a Sun-synchronous, polar-orbiting
satellite is NASA’s Aqua satellite, which orbits approximately 705 km above Earth’s surface.Non-polar

low-Earth orbit satellites, on the other hand, do not provide global coverage but instead
cover only a partial range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core Observatory is an example of a non-Sun-synchronous
low-Earth orbit satellite. Its orbital track acquires data between 65 degrees north and south
latitude from 407 km above the planet.A medium-Earth orbit satellite takes approximately 12

hours to complete an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is consistent and highly predictable. As a result, this
is an orbit used by many telecommunications and GPS satellites. One example of a medium-Earth
orbit satellite constellation is the European Space Agency's Galileo global navigation satellite
system (GNSS), which orbits 23,222 km above Earth.While both geosynchronous and geostationary

satellites orbit at 35,786 km above Earth, geosynchronous satellites have orbits that can
be tilted above or below the equator. Geostationary satellites, on the other hand, orbit Earth
on the same plane as the equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The joint NASA/NOAA Geostationary
Operational Environmental Satellite (GOES) series of weather satellites are in geostationary

orbits above the equator.For more information about orbits, please see NASA Earth Observatory's
Catalog of Earth Satellite Orbits.Electromagnetic energy, produced by the vibration of charged
particles, travels in the form of waves through the atmosphere and the vacuum of space. These
waves have different wavelengths (the distance from wave crest to wave crest) and frequencies;
a shorter wavelength means a higher frequency. Some, like radio, microwave, and infrared waves,

have a longer wavelength, while others, such as ultraviolet, x-rays, and gamma rays, have
a much shorter wavelength. Visible light sits in the middle of that range of long to shortwave
radiation. This small portion of energy is all that the human eye is able to detect. Instrumentation
is needed to detect all other forms of electromagnetic energy. NASA instrumentation utilizes
the full range of the spectrum to explore and understand processes occurring here on Earth

and on other planetary bodies.Some waves are absorbed or reflected by atmospheric components,
like water vapor and carbon dioxide, while some wavelengths allow for unimpeded movement through
the atmosphere; visible light has wavelengths that can be transmitted through the atmosphere.
Microwave energy has wavelengths that can pass through clouds, an attribute utilized by many
weather and communication satellites.The primary source of the energy observed by satellites,

is the Sun. The amount of the Sun’s energy reflected depends on the roughness of the surface
and its albedo, which is how well a surface reflects light instead of absorbing it. Snow,
for example, has a very high albedo and reflects up to 90% of incoming solar radiation. The
ocean, on the other hand, reflects only about 6% of incoming solar radiation and absorbs the
rest. Often, when energy is absorbed, it is re-emitted, usually at longer wavelengths. For

example, the energy absorbed by the ocean gets re-emitted as infrared radiation.All things
on Earth reflect, absorb, or transmit energy, the amount of which varies by wavelength. Just
as your fingerprint is unique to you, everything on Earth has a unique spectral fingerprint.
Researchers can use this information to identify different Earth features as well as different
rock and mineral types. The number of spectral bands detected by a given instrument, its spectral

resolution, determines how much differentiation a researcher can identify between materials.For
more information on the electromagnetic spectrum, with companion videos, view NASA's Tour
of the Electromagnetic Spectrum.Sensors, or instruments, aboard satellites and aircraft use
the Sun as a source of illumination or provide their own source of illumination, measuring
energy that is reflected back. Sensors that use natural energy from the Sun are called passive

sensors; those that provide their own source of energy are called active sensors. Passive
sensors include different types of radiometers (instruments that quantitatively measure the
intensity of electromagnetic radiation in select bands) and spectrometers (devices that are
designed to detect, measure, and analyze the spectral content of reflected electromagnetic
radiation). Most passive systems used by remote sensing applications operate in the visible,

infrared, thermal infrared, and microwave portions of the electromagnetic spectrum. These
sensors measure land and sea surface temperature, vegetation properties, cloud and aerosol
properties, and other physical attributes. Most passive sensors cannot penetrate dense cloud
cover and thus have limitations observing areas like the tropics where dense cloud cover is
frequent.Active sensors include different types of radio detection and ranging (radar) sensors,

altimeters, and scatterometers. The majority of active sensors operate in the microwave band
of the electromagnetic spectrum, which gives them the ability to penetrate the atmosphere
under most conditions. These types of sensors are useful for measuring the vertical profiles
of aerosols, forest structure, precipitation and winds, sea surface topography, and ice, among
others.The Remote Sensors Earthdata page provides a list of NASA’s Earth science passive and

active sensors while the What is Synthetic Aperture Radar? Backgrounder provides specific
information on this type of active sensor.Resolution plays a role in how data from a sensor
can be used. Resolution can vary depending on the satellite’s orbit and sensor design. There
are four types of resolution to consider for any dataset—radiometric, spatial, spectral, and
temporal.Radiometric resolution is the amount of information in each pixel, that is, the number

of bits representing the energy recorded. Each bit records an exponent of power 2. For example,
an 8 bit resolution is 28, which indicates that the sensor has 256 potential digital values
(0-255) to store information. Thus, the higher the radiometric resolution, the more values
are available to store information, providing better discrimination between even the slightest
differences in energy. For example, when assessing water quality, radiometric resolution is

necessary to distinguish between subtle differences in ocean color.Spatial resolution is defined
by the size of each pixel within a digital image and the area on Earth’s surface represented
by that pixel.For example, the majority of the bands observed by the Moderate Resolution Imaging
Spectroradiometer (MODIS) have a spatial resolution of 1km; each pixel represents a 1 km x
1km area on the ground. MODIS also includes bands with a spatial resolution of 250 m or 500

m. The finer the resolution (the lower the number), the more detail you can see. In the image
below, you can see the difference in pixelation between a 30 m/pixel image (left image), a
100 m/pixel image (center image), and a 300 m/pixel image (right image).Spectral resolution
is the ability of a sensor to discern finer wavelengths, that is, having more and narrower
bands. Many sensors are considered to be multispectral, meaning they have 3-10 bands. Some

sensors have hundreds to even thousands of bands and are considered to be hyperspectral. The
narrower the range of wavelengths for a given band, the finer the spectral resolution. For
example, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) captures information
in 224 spectral channels. The cube on the right represents the detail within the data. At
this level of detail, distinctions can be made between rock and mineral types, vegetation

types, and other features. In the cube, the small region of high response in the right corner
of the image is in the red portion of the visible spectrum (about 700 nanometers), and is
due to the presence of 1-centimeter-long (half-inch) red brine shrimp in the evaporation pond.Temporal
resolution is the time it takes for a satellite to complete an orbit and revisit the same
observation area. This resolution depends on the orbit, the sensor’s characteristics, and

the swath width. Because geostationary satellites match the rate at which Earth is rotating,
the temporal resolution is much finer. Polar orbiting satellites have a temporal resolution
that can vary from 1 day to 16 days. For example, the MODIS sensor aboard NASA's Terra and
Aqua satellites has a temporal resolution of 1-2 days, allowing the sensor to visualize Earth
as it changes day by day. The Operational Land Imager (OLI) aboard the joint NASA/USGS Landsat

8 satellite, on the other hand, has a narrower swath width and a temporal resolution of 16
days; showing not daily changes but bi-monthly changes.Why not build a sensor combining high
spatial, spectral, and temporal resolution? It is difficult to combine all of the desirable
features into one remote sensor. For example, to acquire observations with high spatial resolution
(like OLI, aboard Landsat 8) a narrower swath is required, which requires more time between

observations of a given area resulting in a lower temporal resolution. Researchers have to
make trade-offs. This is why it is very important to understand the type of data needed for
a given area of study. When researching weather, which is dynamic over time, a high temporal
resolution is critical. When researching seasonal vegetation changes, on the other hand, a
high temporal resolution may be sacrificed for a higher spectral or spatial resolution.Remote

sensing data acquired from instruments aboard satellites require processing before the data
are usable by most researchers and applied science users. Most raw NASA Earth observation
satellite data (Level 0, see data processing levels) are processed at NASA's Science Investigator-led
Processing Systems (SIPS) facilities. All data are processed to at least a Level 1, but most
have associated Level 2 (derived geophysical variables) and Level 3 (variables mapped on uniform

space-time grid scales) products. Many even have Level 4 products. NASA Earth science data
are archived at discipline-specific Distributed Active Archive Centers (DAACs) and are available
fully, openly, and without restriction to data users.Most data are stored in Hierarchical
Data Format (HDF) or Network Common Data Form (NetCDF) format. Numerous data tools are available
to subset, transform, visualize, and export to various other file formats.Once data are processed,

they can be used in a variety of applications, from agriculture to water resources to health
and air quality. A single sensor will not address all research questions within a given application.
Users often need to leverage multiple sensors and data products to address their question,
bearing in mind the limitations of data provided by different spectral, spatial, and temporal
resolutions.Many sensors acquire data at different spectral wavelengths. For example, Band

1 of the OLI aboard Landsat 8 acquires data at 0.433-0.453 micrometers while the MODIS Band
1 acquires data at 0.620-0.670 micrometers. OLI has a total of 9 bands whereas MODIS has 36
bands, all measuring different regions of the electromagnetic spectrum. Bands can be combined
to produce imagery of the data to reveal different features in the landscape. Often imagery
of data are used to distinguish characteristics of a region being studied or to determine

an area of study.True-color images show Earth as it appears to the human eye. For a Landsat
8 OLI true-color (red, green, blue [RGB]) image, the sensor Bands 4 (Red), 3 (Green), and
2 (Blue) are combined. Other spectral band combinations can be used for specific science applications,
such as flood monitoring, urbanization delineation, and vegetation mapping. For example, creating
a false-color Visible Infrared Imaging Radiometer Suite (VIIRS, aboard the Suomi National

Polar-orbiting Partnership [Suomi NPP] satellite) image using bands M11, I2, and I1 is useful
for distinguishing burn scars from low vegetation or bare soil as well as for exposing flooded
areas. To see more band combinations from Landsat sensors, check out NASA Scientific Visualization
Studio's video Landsat Band Remix or the NASA Earth Observatory article Many Hues of London.
For other common band combinations, see NASA Earth Observatory's How to Interpret Common False-Color

Images, which provides common band combinations along with insight into interpreting imagery.Once
data are processed into imagery with varying band combinations these images can aid in resource
management decisions and disaster assessment. This requires proper interpretation of the imagery.
There are a few strategies for getting started (adapted from NASA Earth Observatory article
How to Interpret a Satellite Image: Five Tips and Strategies):Different land cover types can

be discriminated more readily by using image classification algorithms. Image classification
uses the spectral information of individual image pixels. A program using image classification
algorithms can automatically group the pixels in what is called an unsupervised classification.
The user can also indicate areas of known land cover type to “train” the program to group
like pixels; this is called a supervised classification. Maps or imagery can also be integrated

into a geographical information system (GIS) and then each pixel can be compared with other
GIS data, such as census data. For more information on integrating NASA Earth science data
into a GIS, check out the Earthdata GIS page.Satellites also often carry a variety of sensors
measuring biogeophysical parameters, such as sea surface temperature, nitrogen dioxide or
other atmospheric pollutants, winds, aerosols, and biomass. These parameters can be evaluated

through statistical and spectral analysis techniques.To aid in getting started with applications-based
research using remotely-sensed data, Data Pathfinders provide a data product selection guide
focused on specific science disciplines and application areas, such as those mentioned above.
Pathfinders provide direct links to the most commonly-used datasets and data products from
NASA’s Earth science data collections along with links to tools that provide ways to visualize

or subset the data, with the option to save the data in different file formats.Find and use
NASA Earth science data fully, openly, and without restrictions.Recognizing the connections
between interdependent Earth systems is critical for understanding the world in which we live.The
atmosphere is a gaseous envelope surrounding and protecting our planet from the intense radiation
of the Sun and serves as a key interface between the terrestrial and ocean cycles.The biosphere

encompasses all life on Earth and extends from root systems to mountaintops and all depths
of the ocean. It is critical for maintaining species diversity, regulating climate, and providing
numerous ecosystem functions.The cryosphere encompasses the frozen parts of Earth, including
glaciers and ice sheets, sea ice, and any other frozen body of water. The cryosphere plays
a critical role in regulating climate and sea levels.The human dimensions discipline includes

ways humans interact with the environment and how these interactions impact Earth’s systems.
It also explores the vulnerability of human communities to natural disasters and hazards.The
land surface discipline includes research into areas such as shrinking forests, warming land,
and eroding soils. NASA data provide key information on land surface parameters and the ecological
state of our planet.This vast, critical reservoir supports a diversity of life and helps regulate

Earth’s climate.Processes occurring deep within Earth constantly are shaping landforms. Although
originating from below the surface, these processes can be analyzed from ground, air, or space-based
measurements.The Sun influences a variety of physical and chemical processes in Earth’s atmosphere.
NASA continually monitors solar radiation and its effect on the planet.The terrestrial hydrosphere
includes water on the land surface and underground in the form of lakes, rivers, and groundwater

along with total water storage.Whether you are a scientist, an educator, a student, or are
just interested in learning more about NASA’s Earth science data and how to use them, we have
the resources to help. Get information and guides to help you find and use NASA Earth science
data, services, and tools.We provide a variety of ways for Earth scientists to collaborate
with NASA.Making NASA's free and open Earth science data interactive, interoperable, and accessible

for research and societal benefit both today and tomorrow.The planet NASA studies the most
is Earth. NASA’s end-to-end Earth observations enable agricultural producers to make informed
decisions about global market conditions, water management, in-season crop conditions, severe
weather, and sustainability.This Data Pathfinder will help guide you through the process of
selecting and using datasets applicable to agriculture and water management, and provides

links to specific data sources. If you are new to remote sensing, the What is Remote Sensing?
Backgrounder provides a comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training modules, including Fundamentals of Remote
Sensing.If you have specific questions about how to use data, tools, or resources mentioned
in this Data Pathfinder, please visit the Earthdata Forum. Here, you can interact with other

data users and NASA subject matter experts on a variety of Earth science research and applications
topics.This section provides links to NASA and external tools and applications relevant to
analyzing and visualizing agriculture and water management data referenced in this Data Pathfinder.
NASA's Earth Science Data Systems (ESDS) Program maintains many more resources for data analysis
that may be helpful. Explore the full list on the NASA Earthdata Data Tools page.The Agrometeorological

(AGMET) Earth Observations (EO) Indicators bring together a variety of EO data products on
the sub-national scale, each of which provides valuable insights on in-season crop development
and current crop conditions. Each AGMET Indicator consists of several EO data plots that quantify
critical indicators related to crop health for a specific region and crop over time and are
updated every 7-12 days. Combined, the different EO data plots help tell the story of in-season

crop conditions through the use of different climate, environmental, and vegetative variables.For
more information about AGMET:The Application for Extracting and Exploring Analysis Ready Samples
(AppEEARS) offers a simple and efficient way to access and transform geospatial data from
a variety of federal data archives. AppEEARS enables users to subset geospatial datasets using
spatial, temporal, and band/layer parameters. Two types of sample requests are available:

point samples for geographic coordinates and area samples for spatial areas via vector polygons.
Sample requests submitted to AppEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples
before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,

viewing results, interacting with results, and downloading requests.The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV
offers an API for those who wish to incorporate their data into a separate application or

script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:Earthdata Search
is NASA's tool for searching for and discovering NASA Earth science data as well as relevant
data available through U.S. and international agencies. Users can search for and read about
data collections, search for data files by date and spatial area, preview browse images, and

download or submit requests for data files, with customization for select data collections.
Note: An Earthdata Login is required to download data.In the project area (for some datasets)
users can customize granules. Users can reformat the data and output as HDF, NetCDF, ASCII,
KML, or a GeoTIFF and can choose from a variety of projection options. Data can be subset
to obtain only the bands that are needed.The Famine Early Warning Systems Network (FEWS NET)

provides early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides
evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with

food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,
evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts

throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center. NASA’s
Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single

parameter analysis options include:Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global
croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Resources:The U.S. Drought
Monitor is a weekly map of drought conditions used by policymakers to help determine drought

relief allocations and declarations of drought. NASA satellites provide data about water availability
to the U.S. Drought Monitor.This USGS GFSAD Cropland Data visualization tool by the USGS provides
the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30), visualizing nearly
1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.EarthExplorer
is a complete search and order tool for aerial photos, elevation data, and satellite products

(including the Landsat Data Collection, as well as ASTER data, ASTER GDEM and other products)
distributed by the USGS. This online search, discovery, and ordering tool connects users with
satellite, aircraft, and other remote sensing inventories through interactive and textual-based
query capabilities. These products are available for download at no cost to registered users.
Users may register for a USGS account via the "Register" link on the EarthExplorer main page.The

NASA Worldview data visualization application provides the capability to interactively browse
more than 1,000 global, full-resolution satellite imagery layers and download the underlying
data. Many of the available imagery layers are updated within three hours of observation,
which supports time-critical application areas such as wildfire management, air quality measurements,
and flood monitoring. Worldview imagery is provided through NASA's Global Imagery Browse Services

(GIBS). Worldview also includes geostationary imagery layers from the GOES-East, GOES-West,
and Himawari-8 geostationary satellites that are available at 10-minute increments for the
last 30 days.The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS)
offers a simple and efficient way to access and transform geospatial data from a variety of
federal data archives. AppEEARS enables users to subset geospatial datasets using spatial,

temporal, and band/layer parameters. Two types of sample requests are available: point samples
for geographic coordinates and area samples for spatial areas via vector polygons. Sample
requests submitted to AρρEEARS provide users not only with data values, but also associated
quality data values. Interactive visualizations with summary statistics are provided for each
sample within the application, which allow users to preview and interact with their samples

before downloading their data. Visit the AppEEARS Getting Started to learn more about workflows,
viewing results, interacting with results and downloading requests.Earthdata Search is NASA's
tool for searching for and discovering NASA Earth science data as well as relevant data available
through U.S. and international agencies. Users can search for and read about data collections,
search for data files by date and spatial area, preview browse images, and download or submit

requests for data files, with customization for select data collections. Note: An Earthdata
Login is required to download data.In the project area (for some datasets) users can customize
granules. Users can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF
and can choose from a variety of projection options. Data can be subset to obtain only the
bands that are needed.NASA’s Giovanni is an online application for the display and analysis

of geophysical parameters. There are many options for analysis. For more information on choosing
a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:NASA's ORNL DAAC has several tools for subsetting
data from the MODIS and VIIRS instruments:NetCDF, HDF, GRIB, and other datasets can be viewed

using NASA’s Panoply data viewer. Panoply is a cross-platform application that plots geo-referenced
and other arrays, and offers additional functionality such as slicing and plotting arrays,
combining arrays, and exporting plots and animations. Panoply is a cross-platform application
that runs on Macintosh, Windows, Linux and other desktop computers. Panoply requires that
your computer has have had a compatible Java 11 (or later version) JRE or JDK installed.With

Panoply 5 you can:Resources:NASA's Prediction Of Worldwide Energy Resources (POWER) offers
geospatially-enabled meteorology and solar-related parameters formulated for the agroclimatology
community. It provides various widgets for mapping, analysis, and data download tools, as
well as API services to access the POWER data holdings through custom scripts and scalable
applications. The POWER Data Services consists of a series of restful Application Programming

Interfaces (APIs), geospatial enabled image services, and Open-source Project for a Network
Data Access Protocol (OPeNDAP) services. These three service offerings support data discovery,
access, and distribution as Analysis Ready Data and as direct application inputs to decision-to-support
tools.Data Access ViewerThe Agrometeorological (AGMET) Earth Observations (EO) Indicators
bring together a variety of EO data products on the sub-national scale, each of which provides

valuable insights on in-season crop development and current crop conditions. Each AGMET Indicator
consists of several EO data plots that quantify critical indicators related to crop health
for a specific region and crop over time and are updated every 7-12 days. Combined, the different
EO data plots help tell the story of in-season crop conditions through the use of different
climate, environmental, and vegetative variables.For more information about AGMET:Discover

the NASA Earth Science resources that give insight to agricultural applications. The data
found in this web map can be applied to the following areas:The ClimateSERV data visualization
tool enables users to visualize and download historical rainfall data, vegetation condition
data, and 180-day forecasts of rainfall and temperature to improve understanding of, and make
improved decisions for, issues related to agriculture and water availability. ClimateSERV

offers an API for those who wish to incorporate their data into a separate application or
script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:The Crop Monitor
Exploring Tool is an an online interactive resource that provides NDVI, temperature, precipitation,
soil moisture, ET, and runoff data to determine crop conditions for a variety of different

crops in Early Warning countries (Africa and Asia) and Agricultural Market Information System
(AMIS) countries (North America, Europe, and Asia) by the Group on Earth Observations Global
Agricultural Monitoring (GEOGLAM).The Famine Early Warning Systems Network (FEWS NET) provides
early warning and analysis on food insecurity. Created by the U.S. Agency for International
Development (USAID) to help decision-makers plan for humanitarian crises, FEWS NET provides

evidence-based analysis on more than 30 countries. The FEWS Net Land Data Assimilation System
(FLDAS) is a custom instance of NASA's Land Information System (LIS) that has been adapted
to work with domains, data streams, and monitoring and forecast requirements associated with
food security assessment in data-sparse, developing-countries. The integration of LIS allows
FEWS NET to leverage existing land surface models and generate ensembles of soil moisture,

evapotranspiration (ET), and other variables based on multiple meteorological inputs or land
surface models.The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite
image products, and derived data products in support of FEWS NET drought monitoring efforts
throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early
Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.NASA’s

Giovanni is an online application for the display and analysis of geophysical parameters.
There are many options for analysis. For more information on choosing a type of plot, see
the Giovanni User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single
parameter analysis options include: Multi-parameter analysis options include: Tutorials:Output
options include:GLAM is a web-based platform that enables near-real-time monitoring of global

croplands, primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate
new datasets and improve its speed, flexibility, and computing power.Versions:GLAM2 Original
VersionResources:NetCDF, HDF, GRIB, and other datasets can be viewed using NASA’s Panoply
data viewer. Panoply is a cross-platform application that plots geo-referenced and other arrays,
and offers additional functionality such as slicing and plotting arrays, combining arrays,

and exporting plots and animations. Panoply is a cross-platform application that runs on Macintosh,
Windows, Linux and other desktop computers. Panoply requires that your computer has have had
a compatible Java 11 (or later version) JRE or JDK installed.With Panoply 5 you can:Resources:
NASA's Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology
and solar-related parameters formulated for the agroclimatology community. It provides various

widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled
image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis

Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates
a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to

validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series
data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest

under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are
volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100

cm depth. The visualizer also provides data sources for download.The NASA Worldview data visualization
application provides the capability to interactively browse more than 1,000 global, full-resolution
satellite imagery layers and download the underlying data. Many of the available imagery layers
are updated within three hours of observation, which supports time-critical application areas
such as wildfire management, air quality measurements, and flood monitoring. Worldview imagery

is provided through NASA's Global Imagery Browse Services (GIBS). Worldview also includes
geostationary imagery layers from the GOES-East, GOES-West, and Himawari-8 geostationary satellites
that are available at 10-minute increments for the last 30 days.The Application for Extracting
and Exploring Analysis Ready Samples (AppEEARS) offers a simple and efficient way to access
and transform geospatial data from a variety of federal data archives. AppEEARS enables users

to subset geospatial datasets using spatial, temporal, and band/layer parameters. Two types
of sample requests are available: point samples for geographic coordinates and area samples
for spatial areas via vector polygons. Sample requests submitted to AppEEARS provide users
not only with data values, but also associated quality data values. Interactive visualizations
with summary statistics are provided for each sample within the application, which allow users

to preview and interact with their samples before downloading their data. Visit the AppEEARS
Getting Started to learn more about workflows, viewing the results, interacting with the results
and downloading the requests.The ClimateSERV data visualization tool enables users to visualize
and download historical rainfall data, vegetation condition data, and 180-day forecasts of
rainfall and temperature to improve understanding of, and make improved decisions for, issues

related to agriculture and water availability. ClimateSERV offers an API for those who wish
to incorporate their data into a separate application or script.Crop Condition and Soil Moisture
Analytics (Crop-CASMA) provides access to high-resolution data from NASA’s Soil Moisture Active
Passive (SMAP) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument
in an easy-to-use format. Soil moisture data are critical for professionals in the agriculture

and natural resources sectors who use soil moisture in tandem with other data to plan crop
planting, forecast yields, track droughts or floods, and improve weather forecasts. This application
offers a suite of services such as Web Map Service (WMS), Web Coverage Service (WCS), and
Web Processing Services (WPS).Resources:Earthdata Search is NASA's tool for searching for
and discovering NASA Earth science data as well as relevant data available through U.S. and

international agencies. Users can search for and read about data collections, search for data
files by date and spatial area, preview browse images, and download or submit requests for
data files, with customization for select data collections. Note: An Earthdata Login is required
to download data.In the project area (for some datasets) users can customize granules. Users
can reformat the data and output as HDF, NetCDF, ASCII, KML, or a GeoTIFF and can choose from

a variety of projection options. Data can be subset to obtain only the bands that are needed.The
Famine Early Warning Systems Network (FEWS NET) provides early warning and analysis on food
insecurity. Created by the U.S. Agency for International Development (USAID) to help decision-makers
plan for humanitarian crises, FEWS NET provides evidence-based analysis on more than 30 countries.
The FEWS Net Land Data Assimilation System (FLDAS) is a custom instance of NASA's Land Information

System (LIS) that has been adapted to work with domains, data streams, and monitoring and
forecast requirements associated with food security assessment in data-sparse, developing-countries.
The integration of LIS allows FEWS NET to leverage existing land surface models and generate
ensembles of soil moisture, evapotranspiration (ET), and other variables based on multiple
meteorological inputs or land surface models.The USGS FEWS NET Data Portal provides access

to geo-spatial data, satellite image products, and derived data products in support of FEWS
NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS
NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation
and Science (EROS) Center.NASA’s Giovanni is an online application for the display and analysis
of geophysical parameters. There are many options for analysis. For more information on choosing

a type of plot, see the Giovanni User Manual. Note: An Earthdata Login is required for full
Giovanni functionality.Single parameter analysis options include: Multi-parameter analysis
options include: Tutorials:Output options include:GLAM is a web-based platform that enables
near-real-time monitoring of global croplands, primarily using NASA MODIS satellite data.
This tool is being redesigned to incorporate new datasets and improve its speed, flexibility,

and computing power.Resources:OpenET is a web-based platform that puts NASA evapotranspiration
(ET) data in the hands of farmers, water managers, and conservation groups to speed improvements
and bring about innovation in water management across 17 states in the Western U.S. It uses
publicly-available data and open-source models to deliver satellite-based ET information in
areas as small as a quarter of an acre and at daily, monthly, and yearly intervals.Resources:NASA's

Prediction Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and
solar-related parameters formulated for the agroclimatology community. It provides various
widgets for mapping, analysis, and data download tools, as well as API services to access
the POWER data holdings through custom scripts and scalable applications. The POWER Data Services
consists of a series of restful Application Programming Interfaces (APIs), geospatial enabled

image services, and Open-source Project for a Network Data Access Protocol (OPeNDAP) services.
These three service offerings support data discovery, access, and distribution as Analysis
Ready Data and as direct application inputs to decision-to-support tools.Data Access ViewerNASA's
Oak Ridge National Laboratory DAAC (ORNL DAAC) developed a Soil Moisture Visualizer tool (read
about it at Soil Moisture Data Sets Become Fertile Ground for Applications) that integrates

a variety of North American soil moisture datasets. The visualization tool incorporates in-situ,
airborne, and remote sensing data into one easy-to-use platform. This integration helps to
validate and calibrate the data and provides spatial and temporal data continuity. It also
facilitates exploratory analysis and data discovery for different groups of users. The Soil
Moisture Visualizer offers the capability to geographically subset and download time series

data in .csv format. For more information on the available datasets and use of the visualizer,
view the Soil Moisture Visualizer Guide.To use the visualizer, select a dataset of interest
under Data. Depending on the dataset chosen, the visualizer provides the included latitude/longitude
or an actual site location name and relative time frames of data collection. Upon selecting
a parameter, the tool displays a time series with available datasets. All measurements are

volumetric soil moisture. Surface soil moisture is the daily average of measurements at 0-5
cm depth and root zone soil moisture (RZSM) is the daily average of measurements at 0-100
cm depth. The visualizer also provides data sources for download.The U.S. Drought Monitor
is a weekly map of drought conditions used by policymakers to help determine drought relief
allocations and declarations of drought. NASA satellites provide data about water availability

to the U.S. Drought Monitor.EarthExplorer is a complete search and order tool for aerial photos,
elevation data and satellite products (including the Landsat Data Collection, as well as ASTER
data, ASTER GDEM and other products) distributed by the USGS. This online search, discovery,
and ordering tool connects users with satellite, aircraft, and other remote sensing inventories
through interactive and textual-based query capabilities. These products are available for

download at no cost to registered users. Users may register for a USGS account via the "Register"
link on the EarthExplorer main page.This USGS GFSAD Cropland Data visualization tool by the
USGS provides the Global Food Security Analysis-Support Data at 30 Meters (GFSAD30) visualizing
nearly 1.874 billion hectares (roughly 12.6% of the global terrestrial area) of global croplands.The
Agrometeorological (AGMET) Earth Observations (EO) Indicators bring together a variety of

EO data products on the sub-national scale, each of which provides valuable insights on in-season
crop development and current crop conditions. Each AGMET Indicator consists of several EO
data plots that quantify critical indicators related to crop health for a specific region
and crop over time and are updated every 7-12 days. Combined, the different EO data plots
help tell the story of in-season crop conditions through the use of different climate, environmental,

and vegetative variables.For more information about AGMET:Discover the NASA Earth Science
resources that give insight to agricultural applications. The data found in this web map can
be applied to the following areas:Water Availability: Plant Stress, Soil Moisture, Drought,
Irrigation Weather, Extreme Events and Better Seasonal and Sub-Seasonal Projections: NASA
Models Informing NOAA, USDA and Drought Monitor Operational ForecastingFor GIS users: see

how to use NASA data and services in common GIS tools in the GIS Pathfinder and check out
the How To guides to get help with your workflows.The ClimateSERV data visualization tool
enables users to visualize and download historical rainfall data, vegetation condition data,
and 180-day forecasts of rainfall and temperature to improve understanding of, and make improved
decisions for, issues related to agriculture and water availability. ClimateSERV offers an

API for those who wish to incorporate their data into a separate application or script.Crop
Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution data
from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in

tandem with other data to plan crop planting, forecast yields, track droughts or floods, and
improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni

User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter
analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NetCDF, HDF, GRIB,

and other datasets can be viewed using NASA’s Panoply data viewer. Panoply is a cross-platform
application that plots geo-referenced and other arrays, and offers additional functionality
such as slicing and plotting arrays, combining arrays, and exporting plots and animations.
Panoply is a cross-platform application that runs on Macintosh, Windows, Linux and other desktop
computers. Panoply requires that your computer has have had a compatible Java 11 (or later

version) JRE or JDK installed.With Panoply 5 you can:Resources: NASA's Prediction Of Worldwide
Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related parameters
formulated for the agroclimatology community. It provides various widgets for mapping, analysis,
and data download tools, as well as API services to access the POWER data holdings through
custom scripts and scalable applications. The POWER Data Services consists of a series of

restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service
offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerOpenET is a web-based platform
that puts NASA evapotranspiration (ET) data in the hands of farmers, water managers, and conservation

groups to speed improvements and bring about innovation in water management across 17 states
in the Western U.S. It uses publicly-available data and open-source models to deliver satellite-based
ET information in areas as small as a quarter of an acre and at daily, monthly, and yearly
intervals.Resources:The U.S. Drought Monitor is a weekly map of drought conditions used by
policymakers to help determine drought relief allocations and declarations of drought. NASA

satellites provide data about water availability to the U.S. Drought Monitor.The ClimateSERV
data visualization tool enables users to visualize and download historical rainfall data,
vegetation condition data, and 180-day forecasts of rainfall and temperature to improve understanding
of, and make improved decisions for, issues related to agriculture and water availability.
ClimateSERV offers an API for those who wish to incorporate their data into a separate application

or script.Crop Condition and Soil Moisture Analytics (Crop-CASMA) provides access to high-resolution
data from NASA’s Soil Moisture Active Passive (SMAP) mission and the Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument in an easy-to-use format. Soil moisture data are critical
for professionals in the agriculture and natural resources sectors who use soil moisture in
tandem with other data to plan crop planting, forecast yields, track droughts or floods, and

improve weather forecasts. This application offers a suite of services such as Web Map Service
(WMS), Web Coverage Service (WCS), and Web Processing Services (WPS).Resources:NASA’s Giovanni
is an online application for the display and analysis of geophysical parameters. There are
many options for analysis. For more information on choosing a type of plot, see the Giovanni
User Manual. Note: An Earthdata Login is required for full Giovanni functionality.Single parameter

analysis options include: Multi-parameter analysis options include: Tutorials:Output options
include:GLAM is a web-based platform that enables near-real-time monitoring of global croplands,
primarily using NASA MODIS satellite data. This tool is being redesigned to incorporate new
datasets and improve its speed, flexibility, and computing power.Resources:NASA's Prediction
Of Worldwide Energy Resources (POWER) offers geospatially-enabled meteorology and solar-related

parameters formulated for the agroclimatology community. It provides various widgets for mapping,
analysis, and data download tools, as well as API services to access the POWER data holdings
through custom scripts and scalable applications. The POWER Data Services consists of a series
of restful Application Programming Interfaces (APIs), geospatial enabled image services, and
Open-source Project for a Network Data Access Protocol (OPeNDAP) services. These three service

offerings support data discovery, access, and distribution as Analysis Ready Data and as direct
application inputs to decision-to-support tools.Data Access ViewerNASA develops partnerships
and resources to address food security and works with decision-makers and data users to tailor
these tools to specific locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use, coastal and lake water quality

monitoring, drought preparedness, and famine early warnings. NASA Earth science data are key
elements in the work carried out and supported by the agency's Applied Sciences Program, which
works with individuals and institutions worldwide to inform decision-making, enhance quality
of life, and strengthen our economy. Applied Sciences agriculture and water management-related
efforts include: The Sustainable Development Goals (SDGs) are a collection of 17 interlinked

global goals designed to be a blueprint for a sustainable future for all of Earth’s inhabitants.
The SDGs are part of the 2030 Agenda for Sustainable Development, an international plan signed
by all United Nations (UN) member states and underpinned by the foundational components of
People, Planet, and Prosperity.SDGs include specific social, economic, and environmental targets.
Through SDG 2: Zero Hunger, the UN proposes to end hunger, achieve food security and improved

nutrition, and promote sustainable agriculture. Key SDG 2 Targets include:While NASA datasets
are not official indicators for SDG monitoring and decision-making, they provide data necessary
to assess progress towards achieving SDG Targets. Along with SDG 2, the data and resources
in the Agriculture and Water Management Data Pathfinder help address Targets in other SDGs,
including:The Sustainable Development Progress Report offers data about countries’ performances

in the SDGs.GIS data related to SDG 2 are available from the United Nations Statistics Division
through Esri’s Federated Information System for the SDG Initiative.The Committee on Earth
Observation Satellites (CEOS) also supports SDG 2. Learn how CEOS Agencies are using Earth
observations for agriculture monitoring.August 31, 2023JPEGSeptember 8, 2023JPEGAugust 31,
2023September 8, 2023August 31, 2023JPEGSeptember 8, 2023JPEGSeptember 8, 2023JPEGIn early

September 2023, Greece endured a four-day storm that dropped 910 millimeters (3 feet) of rain
on central parts of the country. The record rainfall triggered deadly flooding and inundated
towns and farm fields in Thessaly, a region that includes Greece’s agricultural heartland.
The flooding was fueled by a stalled low-pressure storm that became cut-off from the jet stream,
also known as a cut-off low, which dropped heavy rainfall on central Greece between September

4 and 7. The storm dropped the most rain, 910 millimeters (3 feet), on Zagora, near Thessaly’s
port town of Volos, according to Meteo, the country’s weather service. About 100 kilometers
(60 miles) inland, the town of Karditsa saw 659 millimeters (2 feet) of rainfall. The pair
of images above shows flooding near Karditsa and Larissa, some of the hardest hit places in
Thessaly. The image on the right, acquired by the Operational Land Imager (OLI) on Landsat

8, shows flooding near the Pineios River on September 8, a day after the storm receded. The
image on the left, acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9, shows the
same area on August 31. The images show floodwater covering what once were green farm fields
in the low-lying Thessaly plain. Farming is a major industry in the region, and accounts for
about one-sixth of Greece’s agricultural output. Farmers here grow primarily cotton, wheat,

corn, and alfalfa. The detailed image below shows flooded fields near the village of Pedino,
north of Karditsa. Sediment-laden water overtopped the banks of the Pineios, to the north
of the village, and the Mega Rema River to the south. September 8, 2023JPEGSeveral villages
along the Pineios and its tributaries became inundated with water during the storm. According
to news reports, over 4,000 people have been rescued from high water areas. Flooding near

Larissa, Thessaly’s capital and one of the largest cities in Greece, can be seen in the image
below. Suburbs of the city were flooded after the Pineios River broke its banks. September
8, 2023JPEGAlthough water along the Pineios had started to recede on September 11, flooding
along the river could still be seen in images from the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Terra satellite. According to news reports, the river was still 2 meters

(6.5 feet) above safe levels. NASA Earth Observatory images by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Emily Cassidy.View this area in EO ExplorerRecord
rainfall inundated towns and farmland in the country’s Thessaly region.Image of the Day for
September 12, 2023 Image of the Day Water Floods Human Presence View more Images of the Day:The
melting of frozen rivers and snowpack, and the heavy rains of late spring and summer, can

send rivers out of their banks.Flash floods in the port city destroyed roads and swept neighborhoods
out to sea. Image of the Day Land Water Floods Human Presence A Mediterranean cyclone contributed
to deadly flooding along the country’s coastline. Image of the Day Land Water Floods A stalled
storm dropped three feet of rain over four days on the Thessaly region, triggering extensive
flooding. Image of the Day Atmosphere Floods An isolated low-pressure system produced torrential

downpours in Spain and carried Saharan dust along its path. Image of the Day Atmosphere Land
Floods Human Presence September 1, 2023JPEGFor decades, summer phytoplankton blooms have sprung
up in Missisquoi Bay in the northeastern part of Lake Champlain. The bay’s shallow, nutrient-rich,
and seasonally warm waters offer ideal growing conditions for the floating, plant-like organisms,
which can multiply and aggregate into vast masses that discolor parts of the lake.The summer

of 2023 was no exception. The Operational Land Imager (OLI) on Landsat 8 acquired this natural-color
image of a bloom swirling near the mouth of the Missisquoi River on September 1, 2023. The
satellite collected similar images in August as well.While it is not possible to determine
the type of phytoplankton with Landsat observations alone, this bloom is likely cyanobacteria
(also called blue-green algae)—an ancient type of marine bacteria that captures and stores

solar energy through photosynthesis. Several trained cyanobacteria spotters submitted photographs
and reports of dense green mats of cyanobacteria lining the shores of Missisquoi Bay to Verrmont’s
cyanobacteria tracker website around the same time the image was acquired.Cyanobacteria blooms
are monitored closely because some species produce toxins known as cyanotoxins, including
a widespread type called microcystin, that can sicken people and animals, contaminate drinking

water, and force closures of boating and swimming sites.In recent years, teams of researchers
working with NASA’s DEVELOP program have used observations from several satellites to track
where in Lake Champlain harmful blooms are most common and identify key risk factors associated
with them. In a technical report, the researchers reported that Missisquoi Bay and nearby
St. Albans Bay had the lake’s highest concentration of toxic cyanobacteria blooms between

2016-2022.“There are multiple contributors to blooms like nutrients, temperature, and wind
and wave conditions,” noted Kent Ross, a science advisor for the Lake Champlain DEVELOP project.
“We focused on the availability of one of the nutrients—phosphorus.”Phosphorus is a common
nutrient found in runoff from farmland, lawns, and developed areas. While much of Lake Champlain
is surrounded by forests, which filter nutrients, Missisquoi Bay is flanked by farmland, where

fertilizer use leads to higher levels of phosphorous in the rivers that flow into the bay,
Ross explained.“That’s where our project partner, the U.S. Department of Agriculture’s Natural
Resource Conservation Service, comes in,” added Ross. “They recommend best practices to farmers
to limit nutrient runoff.” Adjusting the timing or type of fertilizer, changing grazing rotations,
upgrading drainage systems, and improving soil health are among the strategies farmers might

pursue.One of the challenges for scientists who study cyanobacteria blooms is that blooms
don’t always contain the species that produce harmful toxins. “The currently used indices
based on multispectral imagery cannot distinguish between the toxin-producing subspecies of
microcystis and non-toxin producing microcystis algae blooms,” said Jeffrey Luvall, also a
science advisor for the DEVELOP team and a scientist at NASA’s Marshall Space Flight Center.

“But the upcoming PACE mission—scheduled to launch in 2024—will make hyperspectral observations
able to do that.”NASA Earth Observatory image by Wanmei Liang, using Landsat data from the
U.S. Geological Survey. Story by Adam Voiland.View this area in EO ExplorerPhosphorus runoff
from farmland surrounding Lake Champlain contributes to summer cyanobacteria blooms in the
northeastern part of the lake.Image of the Day for September 11, 2023 Image of the Day Water

Human Presence Water Color View more Images of the Day:Floating, plant-like organisms reproduce
abundantly when there are sufficient nutrients, sunlight, and water conditions. Extreme blooms
of certain species can become harmful to marine animals and humans.More than 40 years after
the explosive eruption of Mount St. Helens, relics from the blast continue to haunt a nearby
lake. Image of the Day Water Straddling Austria and Hungary, the lake is also known as the

“Sea of the Viennese.” Image of the Day Land Water Human Presence Snow and Ice At an average
elevation of 3,812 meters (12,507 feet), Lake Titicaca is one of the highest lakes in the
world. The lake is positioned between two major ranges of the Andes Mountain chain and has
very limited drainage. The limited outflow of the lake allows for the accumulation of nutrients
derived primarily from surrounding communities’ agricultural and sewage waste. The increased

nutrient levels can lead to plankton blooms. This astronaut photograph, taken from the International
Space Station, captures two such blooms along the eastern shoreline of the lake. Image of
the Day Land Life Once the second-largest lake in Turkey, it now rarely spans an area much
larger than a puddle. Image of the Day Land Water Remote Sensing August 18, 2023JPEGWhile
some weather-related delays are mere annoyances, others slow the rhythms of global shipping.

Due to ongoing drought and low water levels, ship traffic was restricted through the Panama
Canal in late summer 2023, leaving an above-average number of vessels waiting to make the
transit. The Panama Canal is an 80-kilometer (50-mile) artificial waterway across the Isthmus
of Panama, providing a vital connection between the Atlantic and Pacific Oceans for up to
14,000 ships each year. The Operational Land Imager (OLI) on Landsat 8 got a rare cloud-free

view of delayed ships on the Pacific side of the canal on August 18, 2023. Artificial lakes
supply the water needed to fill the series of locks in the canal. Those lakes, located to
the north and northwest of this scene, are replenished by rainfall that is typically in abundance
on the Isthmus of Panama. However, drought has left Lago Gatún, the largest lake feeding the
system, at near-record low levels. In mid-August, it stood close to the lowest recorded level,

from May 2016, and well below the average level for August from the past five years. As a
means of conserving water, the Panama Canal Authority reduced the number of vessels that could
travel through the canal each day starting on July 30. At one point in early August, the ensuing
backup reached as high as 160 total vessels waiting on one side or the other. By the time
of this image, that number had decreased to around 130, whereas the queue ordinarily tops

off around 90. The average wait time for August 2023 was nearly four times what it was in
June. The reduction of daily passages was the latest restriction imposed by the Panama Canal
Authority this year to deal with the water shortages. Starting on March 1, 2023, it began
reducing the maximum draft (the distance between the waterline and the bottom of the hull)
permitted for vessels passing through the locks. The normal limit of 50 feet (15 meters) for

the largest class of ships that use the canal was increasingly ratcheted down to 44 feet (13
meters), requiring some ships to lighten their loads. The area has seen a number of dry years
in the past decade; Lago Gatún dipped to low levels in 2016 and 2019, in addition to 2023.
At the other extreme, however, Lago Gatún and Lago Alajuela, another lake feeding the canal,
reached record high levels in December 2010. The flooding caused the canal to close for only

the third time in its history. NASA Earth Observatory image by Wanmei Liang, using Landsat
data from the U.S. Geological Survey. Story by Lindsey Doermann.View this area in EO ExplorerSevere
drought is reducing the number of daily passages on the transoceanic shipping route.Image
of the Day for September 1, 2023 Image of the Day Water Human Presence View more Images of
the Day:In September, low water levels made it more challenging to ship goods down the river

and allowed a wedge of saltwater to move upstream. Image of the Day Water Drought Hundreds
of ships have been left idling around the key shipping route. Nature played a role in solving
the problem. Image of the Day Human Presence A key shipping route through Egypt recently received
a major overhaul. Image of the Day Land Water Human Presence More than 64 million people are
directly affected by drought in the Southwest and Southern Plains, and far more are indirectly

affected because of the vast number of farms, orchards, and ranches that supply the rest of
the United States. Image of the Day Land Life Water Drought August 21, 2023JPEGFor more than
a decade, drought has plagued central Chile. The prolonged dry period—a megadrought—has fueled
wildfires, strained water supplies, and parched crops.In winter 2023, the region got some
relief in the form of two atmospheric rivers that brought hundreds of millimeters of rain

and snow to the region. However, too much rain fell too quickly in some areas, prompting floods
and mudslides that damaged roads and bridges, destroyed thousands of homes, and displaced
tens of thousands of people.The map above shows the total precipitable water vapor in the
atmosphere on August 21, 2023. Precipitable water vapor is the amount of water in a column
of the atmosphere if all of the water vapor were condensed into liquid. The image was derived

from the Goddard Earth Observing System (GEOS), which uses satellite data and models of physical
processes to calculate what is happening in Earth's atmosphere, oceans, and land surfaces.The
narrow band of moisture (green) stretching from the central Pacific Ocean to Chile is a signature
of an atmospheric river—a long, narrow region that transports vast amounts of water vapor
from the tropics poleward. In subtropical Chile, atmospheric rivers contribute 45 to 60 percent

of the annual precipitation, most of it in the winter rainy season (June to September).El
Paico in the Santiago metropolitan region saw nearly 80 millimeters (3 inches) of rain fall
between August 19-21, while areas farther inland in the foothills of the Andes saw as much
as 370 millimeters (15 inches) of rain, according to Floodlist. Meanwhile, some news outlets
reported that 2 or more meters (up to 8 feet) of snow fell in high mountain areas.August 26,

2023JPEGSome of the worst flooding occurred in the Maule, Ñuble, and Biobío regions of Chile.
“There was a strong orographic effect,” said atmospheric scientist René Garreaud of Universidad
de Chile. “We saw five to ten times more rain in the Andean foothills compared to Chile’s
Central Valley.”Higher elevation areas saw boosted rainfall totals because the Andes forced
the incoming river of moisture upward, where lower air pressure and cooler temperatures cause

water vapor to more easily condense into rain droplets on the windward side of mountains.
This same effect produces rain shadows on the lee side of mountains.Several days after the
surge of rain, rivers were still swollen and discolored. Floodwaters can pick up material,
such as sediment from riverbanks, that becomes suspended in the water and makes it appear
brown. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite

captured an image (above) showing rivers carrying plumes of suspended sediment into the Pacific
Ocean on August 26, 2023.The atmospheric river in August followed a similar event in June.
According to Garreaud, the June event delivered more than 500 millimeters (20 inches) of rain
over a two-day period to the Maule foothills, roughly double what normally falls in Santiago
in a year.The El Niño developing in the Pacific may be affecting how these events play out.

“We are seeing extra moisture in the central Pacific, but the coupling with the atmosphere
is still relatively weak,” Garreuad said. “The Pacific anticyclone remains strong, and we
haven’t yet seen a blocking high to the south of the continent—the typical signature of winter
storms that are strongly influenced by El Niño.”The concept of atmospheric rivers first emerged
in the 1990s and has become a topic of growing interest to researchers in recent years. Some

research suggests that climate change may be causing atmospheric rivers to produce more rain
and shift poleward. One analysis of model projections conducted by a team of scientists at
NASA's Jet Propulsion Laboratory found that atmospheric rivers may decrease in frequency but
grow longer and wider under a scenario in which future greenhouse gas emissions remain high.NASA
Earth Observatory images by Lauren Dauphin and Wanmei Liang, using GEOS-FP data from the Global

Modeling and Assimilation Office at NASA GSFC and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerAfter more than a decade of drought, strong
atmospheric rivers in June and August flooded the foothills of the Andes in the Maule, Ñuble,
and Biobío regions.Image of the Day for September 4, 2023 Image of the Day Atmosphere Land
Water Floods View more Images of the Day:Heavy rain and melting snow can overtop riverbanks,

causing far-reaching consequences for ecosystems and people.In late June 2019, a potent atmospheric
river event carried soaking rain into southern Chile, dropping nearly a month’s worth of precipitation
in just 48 hours. Image of the Day Water The latest in a series of atmospheric rivers drenching
the state was accompanied by hazardous winds and left thousands of people without power. Image
of the Day Atmosphere Water Severe Storms Two atmospheric rivers hit Australia’s east and

west coasts with severe rains on the same day. Image of the Day Atmosphere Land Water Unique
Imagery Following an exceptionally wet January, an atmospheric river carried even more moisture
into the region in February. Image of the Day Atmosphere Severe Storms Remote Sensing August
21, 2023JPEGIn March and April 2023, some earth scientists began to point out that average
sea surface temperatures had surpassed the highest levels seen in a key data record maintained

by NOAA. Months later, they remain at record levels, with global sea surface temperatures
0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at
record levels.Scientists from NASA have taken a closer look at why. “There are a lot of things
that affect the world’s sea surface temperatures, but two main factors have pushed them to
record heights,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL).

“We have an El Niño developing in the Pacific, and that’s on top of long-term global warming
that has been pushing ocean temperatures steadily upward almost everywhere for a century.”The
map above shows sea surface temperature anomalies on August 21, 2023, when many areas were
more than 3°C (5.4°F) warmer than normal. On that date, much of the central and eastern regions
of the equatorial Pacific were unusually warm, the signature of a developing El Niño. As has

been the case for weeks, large patches of warm water were also present in the Northwest Pacific
near Japan and the Northeast Pacific near California and Oregon. Portions of the Indian, Southern,
and Arctic Oceans also showed unusual warmth.The map is based on data from the Multiscale
Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, a JPL effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well

as ship and buoy observations. Rather than showing absolute temperature, the anomaly reflects
the difference between the sea surface temperature on August 21, 2023, and the 2003-2014 average
for that day. The video below, also based on MUR SST data, shows global sea surface temperatures
since April 1, 2023, the period when they have been at record-breaking levels. The warmest
waters appear dark red.April 1 - August 21, 2023MPEG “Over the long term, we’re seeing more

heat and warmer sea surface temperatures pretty much everywhere,” said Gavin Schmidt, the
director of NASA’s Goddard Institute for Space Studies. “That long-term trend is almost entirely
attributable to human forcing—the fact that we've put such a huge amount of greenhouse gas
in the atmosphere since the start of the industrial era.”Schmidt noted that other factors—such
as weather and wind patterns or the distribution of dust and aerosols—have short-term effects

on sea surface temperatures in certain regions, but they generally have a minor effect on
the longer-term global mean. Previous research shows that as much as 90 percent of the excess
heat that has occurred in recent decades due to increasing greenhouse gas emissions is absorbed
by the ocean, with much of that heat stored near the surface.The most important factor that
helped push sea surface temperatures into record territory in 2023 was the evolving El Niño

in the Pacific, according to Willis. He came to that conclusion by analyzing the timing and
intensity of sea surface temperature anomalies in several regions and comparing them to the
global trend.“We had a big jump in global surface temperature at the beginning of April—exactly
when the Pacific temperatures jumped up and also when sea levels in the eastern Pacific started
to rise,” Willis said. “The heat waves in the Atlantic are important and will have serious

effects on marine life and weather in Europe in the coming months. But it’s the Pacific that
has taken the global mean on a wild ride this year.”What happens in the Pacific tends to have
a large influence on the global sea surface temperatures partly because of its size. The Pacific
represents about half of the world’s ocean area.Marine heat waves—defined as periods of persistent
anomalously warm ocean temperatures (warmer than 90 percent of the previous observations for

a given time of year)—have occurred recently in several areas. One NOAA analysis showed that
48 percent of the global oceans were in the midst of a marine heat wave in August—a larger
area than for any other month since the start of the record in 1991. Particularly intense
events have warmed the North Atlantic and parts of the Caribbean in recent months.Willis expects
the heat in the equatorial Pacific to have more staying power than many of the other marine

heat waves simmering around the world. “Many of the marine heat waves we’re seeing are ephemeral
and ‘skin’ deep, generally lasting on the order of weeks and driven by atmospheric forces,”
explained Willis.The unusually warm water in the equatorial Pacific associated with the developing
El Niño after three consecutive years of La Niña is expected to weaken trade winds in ways
that reinforce and amplify the warming of surface waters, fueling the El Niño further. Forecasters

from NOAA say that there is a greater than 95 percent chance that El Niño conditions will
persist throughout the Northern Hemisphere winter. “What’s happening in the Pacific with El
Niño will influence global weather patterns and sea surface temperatures well into the winter
and possibly even longer,” Willis said.To monitor sea surface temperatures, scientists at
NOAA and NASA analyze observations from sensors and buoys in the oceans, ships, and several

different polar-orbiting and geostationary satellites. Groups of scientists with NOAA’s Physical
Sciences Laboratory, NOAA’s Coral Reef Watch, and NASA’s Jet Propulsion Laboratory track marine
heat waves and sea surface temperature anomalies closely. You can use NASA’s State of the
Ocean Tool on Worldview to monitor daily sea surface temperature anomalies.NASA Earth Observatory
image by Lauren Dauphin, using data from the Multiscale Ultrahigh Resolution (MUR) project.

Video by NASA’s Scientific Visualization studio, using data from the MUR project. Story by
Adam Voiland.Decades of gradual warming due to human-caused climate change and an El Niño
in the Pacific Ocean nudged global sea surface temperatures to record levels in 2023.Image
of the Day for August 25, 2023 Image of the Day Water View more Images of the Day:Earth in
July 2023 was 1.18°C (2.12°F) warmer than the average for the month, and warmer than any other

month in the 143-year record. Image of the Day Heat Temperature Extremes The climate phenomenon
emerged in late spring 2023, as waters grew warmer and sea levels rose higher than usual in
the tropical Pacific Ocean. Image of the Day Water Blooms of the plant-like organisms near
coastal areas have become more frequent in the 21st century. Image of the Day Water Remote
Sensing Examining temperatures from the depths of the ocean, JPL scientists have found that

lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when
surface temperatures cooled. Image of the Day Heat Water August 20, 2023JPEGOnce a powerful
category 4 hurricane, Hilary weakened and made landfall in northern Mexico on August 20, 2023,
pelting the Baja California peninsula and two U.S. states with rain.Before making landfall,
Hilary delivered torrential rain to Santa Rosalía in Mexico’s state of Baja California Sur.

One person was killed by the floodwater, according to officials. Hilary weakened to a tropical
storm before it came ashore on the northern end of the peninsula at around 11 a.m. Pacific
Time on August 20, 2023. As the storm moved inland over Southern California, it left flooding,
mudslides, and power outages behind. The map above depicts a satellite-based estimate of the
storm’s rainfall rates. Data for the map were acquired between 5 p.m. Pacific Time on August

19 and 2 p.m. Pacific Time on August 20, as the center of the storm was approaching Southern
California. The darkest reds reflect the highest rainfall rates, with the Baja California
peninsula seeing the heaviest rains during this time. The data are remotely sensed estimates
that come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the
Global Precipitation Measurement (GPM) satellite mission. Due to the averaging of the satellite

data, local rainfall rates may be significantly higher when measured from the ground. August
20 was the wettest August day on record for both downtown Los Angeles and San Diego, according
to the National Weather Service. They received 2.5 inches (6.3 centimeters) and 1.8 inches
(4.6 centimeters) of rain, respectively. The storm also brought wind gusts of 70 miles (113
kilometers) per hour to parts of California, knocking over trees and power lines, and reportedly

leaving 40,000 residents without power. Death Valley National Park closed due to flooding,
and several roads were also flooded and damaged in Las Vegas, Nevada. So far, some of the
most severely affected places in the U.S. have been the normally dry desert regions of Southern
California. Streets turned into rivers of mud in Palm Springs after the city received six
months of rain over six hours. Flooding also closed roads in Coachella Valley, including I-10,

the major highway in the region. August is typically a dry month in Southern California, but
the surface layers of soil can respond quickly to weather events. Scientists at NASA’s Short-term
Prediction Research and Transition Center (SPoRT) expected that rain from the storm could
saturate soils in the region for several days. Hilary continued to move north into Oregon
and Idaho on August 21, where rainfall totals of up to 3 inches (7.6 centimeters) were anticipated

in places, with potential for flash flooding. NASA Earth Observatory image by Lauren Dauphin,
using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC. Story by Emily
Cassidy.View this area in EO ExplorerThe storm delivered torrential rain to parts of Southern
California, Nevada, and Mexico, leaving flooded streets and power outages in its wake.Image
of the Day for August 22, 2023 Image of the Day Water Severe Storms View more Images of the

Day:The hurricane season in the Pacific runs from June through November, though the storms
can form any time of year.The major hurricane was expected to weaken before delivering heavy
rain to Mexico and Southern California. Image of the Day Atmosphere Severe Storms Acquired
January 20, 2010, this true-color image shows an apostrophe-shaped storm, looking slightly
like a hurricane without most of its center, over the California coast. Isolated areas of

clear sky show the Central Valley and Baja Peninsula. Atmosphere Severe Storms Severe Storms
Acquired January 19, 2010, this image shows three cloud banks on their eastward path over
California. One is over the ocean, one hovers over the coast, and one has traveled inland.
Image of the Day Atmosphere Land Severe Storms July 26, 2023JPEGVibrant turquoise and green
water swirled near the coastline of Vancouver Island in late July 2023. The colorful plumes—which

are likely comprised of both phytoplankton and sediment—stood out in this image, acquired
by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite on July
26. Clouds covered much of Vancouver Island and mainland British Columbia at the time of this
image. But coastal areas were cloud-free, exposing water that likely contained flourishing
populations of phytoplankton—floating plant-like organisms that are the foundation of the

aquatic food web. Phytoplankton blooms are common in the northeast Pacific Ocean during summer
as offshore winds push surface waters away from the coast. This causes cooler, nutrient-rich
waters to well up from the depths and fuel the growth of phytoplankton. Research has shown
that a significant amount of nutrients are supplied by the circulation and upwelling that
occurs in the Salish Sea, boosting phytoplankton productivity along the continental shelf

off Vancouver Island. The bloom also could have been fed by nutrient-rich sediment running
off from the coast. The greenest areas off the island’s coast may contain diatoms—a microscopic
form of algae with silica shells and plenty of chlorophyll. Coccolithophores—a type of phytoplankton
armored with calcium carbonate plates—tend to make the water appear more milky-blue and might
be present in the bloom. A future NASA satellite mission called PACE—short for Plankton, Aerosol,

Cloud, ocean Ecosystem—will enable researchers to infer more information about ocean ecology,
including the species of phytoplankton present in blooms and the rates of their growth. PACE
is scheduled to launch no earlier than January 2024. NASA Earth Observatory image by Lauren
Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite
System (JPSS). Story by Emily Cassidy.View this area in EO ExplorerSwirls of phytoplankton

and sediment brightened the island’s coastal waters in July 2023.Image of the Day for August
2, 2023 Image of the Day Water Water Color View more Images of the Day:Floating, plant-like
organisms reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.Skirting
the coastline of Mozambique, these 32 small islands are home to a diversity of corals and

sea turtles. Image of the Day Life Water These rough waters were once traversed by Japanese
pirates; now they are spanned by bridges. Image of the Day Land Water Human Presence Acquired
October 2, 2002, this natural-color image shows islands off the coast of Croatia, in the Adriatic
Sea. Image of the Day Land Image of the Day Land Unique Imagery At the base of the ocean food
web are single-celled algae and other plant-like organisms known as phytoplankton. Like plants

on land, phytoplankton use chlorophyll and other light-harvesting pigments to carry out photosynthesis,
absorbing atmospheric carbon dioxide to produce sugars for fuel. Chlorophyll in the water
changes the way it reflects and absorbs sunlight, allowing scientists to map the amount and
location of phytoplankton. These measurements give scientists valuable insights into the health
of the ocean environment, and help scientists study the ocean carbon cycle.These chlorophyll

maps show milligrams of chlorophyll per cubic meter of seawater each month. Places where chlorophyll
amounts were very low, indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were growing, are dark green.
The observations come from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's
Aqua satellite. Land is dark gray, and places where MODIS could not collect data because of

sea ice, polar darkness, or clouds are light gray.The highest chlorophyll concentrations,
where tiny surface-dwelling ocean plants are thriving, are in cold polar waters or in places
where ocean currents bring cold water to the surface, such as around the equator and along
the shores of continents. It is not the cold water itself that stimulates the phytoplankton.
Instead, the cool temperatures are often a sign that the water has welled up to the surface

from deeper in the ocean, carrying nutrients that have built up over time. In polar waters,
nutrients accumulate in surface waters during the dark winter months when plants can't grow.
When sunlight returns in the spring and summer, the plants flourish in high concentrations.A
band of cool, plant-rich waters circles the globe at the Equator, with the strongest signal
in the Atlantic Ocean and the open waters of the Pacific Ocean. This zone of enhanced phytoplankton

growth comes from the frequent upwelling of cooler, deeper water as a result of the dominant
easterly trade winds blowing across the ocean surface. In many coastal areas, the rising slope
of the sea floor pushes cold water from the lowest layers of the ocean to the surface. The
rising, or upwelling water carries iron and other nutrients from the ocean floor. Cold coastal
upwelling and subsequent phytoplankton growth are most evident along the west coasts of North

and South America and southern Africa.View, download, or analyze more of these data from NASA
Earth Observations (NEO): Chlorophyll Life Water September 12, 2023JPEGOn September 12, 2023,
Hurricane Lee continued its slow west-northwest trajectory across the Atlantic Ocean. The
Geostationary Operational Environmental Satellite 16 (GOES-16) acquired this image of the
major storm at approximately 1 p.m. Eastern Time (17:00 UTC) as it advanced toward the southeastern

United States. The satellite is operated by the National Oceanic and Atmospheric Administration
(NOAA); NASA helps develop and launch the GOES series of satellites. Around this time, the
center of the hurricane was located about 500 miles (800 kilometers) south of Bermuda and
moving at 6 miles (9 kilometers) per hour. Sustained winds were measured at 115 miles (185
kilometers) per hour, making it a category 3 storm on the Saffir-Simpson hurricane wind scale.On

its path across the ocean to this point, the hurricane fluctuated dramatically in strength,
as it underwent one of the most extreme periods of rapid intensification for a North Atlantic
storm in the past 40 years. In the 24 hours ending at 2 a.m. Eastern Time (06:00 UTC) on September
8, Lee’s winds increased from 80 to 165 miles per hour (130 to 265 kilometers per hour), escalating
it to category 5 status. Only Hurricane Felix in 2007 and Hurricane Wilma in 2005 intensified

more over a 24-hour period. Following this ramp-up, moderate to strong wind shear disrupted
the storm’s circulation and weakened it to a category 2. September 10, 2023JPEGThat would
not be the last momentum swing, however. On September 10, Hurricane Lee began to regain strength
as wind shear abated and it passed over very warm waters. The map above shows sea surface
temperatures on from that day based on data from the Multiscale Ultrahigh Resolution Sea Surface

Temperature (MUR SST) project, a NASA Jet Propulsion Laboratory effort that blends measurements
of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well
as ship and buoy observations. High sea surface temperatures are among the conditions favorable
to hurricane intensification. And 2023 has been a banner year for warm oceans. Decades of
gradual warming due to climate change, along with El Niño conditions in the Pacific Ocean,

helped drive global sea surface temperatures into record territory for several months in the
summer. Meteorologists generally agree that sea surface temperatures above 27.8 degrees Celsius
(82 degrees Fahrenheit) will sustain and intensify hurricanes, cyclones, and typhoons. Surface
waters above that threshold are shown in red to black on the map. Forecast models indicate
that a weather pattern over the eastern U.S. will redirect Lee to the north. The storm is

expected to expand in size and weaken as it moves over cooler waters recently churned up by
hurricanes Franklin and Idalia. The storm will likely pass west of Bermuda, which is under
a tropical storm watch, and potentially make landfall over the northeastern U.S. or Nova Scotia
as a much weaker storm. NASA Earth Observatory images by Lauren Dauphin, using GOES 16 imagery
courtesy of NOAA and the National Environmental Satellite, Data, and Information Service (NESDIS)

and data from the Multiscale Ultrahigh Resolution (MUR) project. Story by Lindsey Doermann.View
this area in EO ExplorerThe major storm fluctuated in intensity as it approached the U.S.
East Coast.Image of the Day for September 13, 2023 Image of the Day Land Water Severe Storms
View more Images of the Day:Hurricane season in the basin runs from June 1 to November 30.Acquired
August 23, 2009, this true-color image shows Hurricane Bill missing the U.S., apparently headed

northward toward Canada. Atmosphere Water Severe Storms The first hurricane of the Atlantic
season made a series of landfalls and dropped abundant rain from the Caribbean to the U.S.
East Coast. Heat Water Severe Storms Human Presence The SeaWiFS instrument captured the data
for this composite view of an August 2000 hurricane while it was near Bermuda. Image of the
Day Atmosphere Though it has weakened since reaching category 5 strength, the hurricane is

still bringing heavy rain and strong winds to the northeast Atlantic. Image of the Day Floods
Severe Storms Remote Sensing September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 7, 2023September
13, 2023September 7, 2023JPEGSeptember 13, 2023JPEGSeptember 13, 2023JPEGOn September 10,
2023, a low-pressure storm brought heavy rains to northeastern Libya, causing deadly flooding
and devastation in cities along the Mediterranean coast. On the coast of Libya’s Cyrenaica

region, Al Bayda recorded 414 millimeters (16 inches) of rain in one day. Nearby, the port
city of Derna received more than 100 millimeters (4 inches) over the course of the storm—far
exceeding the city’s average monthly rainfall for September of less than 1.5 millimeters (0.1
inches). Derna lies at the end of a long, narrow valley, called a wadi, which is dry for most
of the year. Floods triggered two dams along Wadi Derna to collapse, sending floodwater and

mud to the city. According to news reports, floodwater swept away roads and entire neighborhoods.
The images above show the Cyrenaica region before and after the storm. They are false color,
which makes water (blue) stand out from the surroundings. The image on the right, acquired
on September 13, shows water filling low-lying areas and wadis inland from the coast. The
image on the left shows the same area on September 7. Both images were acquired with the Moderate

Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The flooding and damage
in Derna is difficult to see at this resolution, although sediment flowing into the Mediterranean
is visible in natural color images. In the days prior to making landfall in Libya, the same
low-pressure storm (named Storm Daniel by the Hellenic National Meteorological Service) swamped
parts of Greece, Turkey, and Bulgaria. As the storm approached Libya, it developed characteristics

of a tropical-like cyclone, or “medicane,” with winds measuring around 70 to 80 kilometers
(43 to 50 miles) per hour. September 10, 2023JPEGThe natural-color image above, acquired with
MODIS on NASA’s Terra satellite, shows the storm on September 10 as it made landfall in northeastern
Libya. Only one or two medicanes typically develop in a year, according to NOAA. As of September
13, authorities were still conducting search and rescue operations in the region. Derna was

still largely inaccessible on that day, making it difficult to assess the full impact of the
flood.NASA Earth Observatory images by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE
and GIBS/Worldview. Story by Emily Cassidy.View this area in EO ExplorerA Mediterranean cyclone
contributed to deadly flooding along the country’s coastline.Image of the Day for September
14, 2023 Image of the Day Land Water Floods View more Images of the Day:The melting of frozen

rivers and snowpack, and the heavy rains of late spring and summer, can send rivers out of
their banks.Flash floods in the port city destroyed roads and swept neighborhoods out to sea.
Image of the Day Land Water Floods Human Presence Record rainfall inundated towns and farmland
in the country’s Thessaly region. Image of the Day Water Floods Human Presence Cities and
towns darkened after a cyclone unleashed torrential flooding along the country’s coast. Image

of the Day Human Presence An extratropical cyclone triggered deadly flooding in the state
of Rio Grande do Sul. Image of the Day Water Floods Sea surface temperatures have a large
influence on climate and weather. For example, every 3 to 7 years a wide swath of the Pacific
Ocean along the equator warms by 2 to 3 degrees Celsius. This warming is a hallmark of the
climate pattern El Niño, which changes rainfall patterns around the globe, causing heavy rainfall

in the southern United States and severe drought in Australia, Indonesia, and southern Asia.
On a smaller scale, ocean temperatures influence the development of tropical cyclones (hurricanes
and typhoons), which draw energy from warm ocean waters to form and intensify.These sea surface
temperature maps are based on observations by the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA’s Aqua satellite. The satellite measures the temperature of the top millimeter

of the ocean surface. In this map, the coolest waters appear in blue (approximately -2 degrees
Celsius), and the warmest temperatures appear in pink-yellow (35 degrees Celsius). Landmasses
and the large area of sea ice around Antarctica appear in shades of gray, indicating no data
were collected.The most obvious pattern shown in the time series is the year-round difference
in sea surface temperatures between equatorial regions and the poles. Various warm and cool

currents stand out even in monthly averages of sea surface temperature. A band of warm waters
snakes up the East Coast of the United States and veers across the North Atlantic—the Gulf
Stream.Although short-lived weather events that influence ocean temperature are often washed
out in monthly averages, a few events show up. For example, in December 2003, strong winds
blew southwest from the Gulf of Mexico over Central America toward the Pacific Ocean, driving

surface waters away from the coast, and allowing cold water from deeper in the ocean to well
up to the surface. These winds are a recurring phenomenon in the area in the winter; they
are known as Tehuano winds.View, download, or analyze more of these data from NASA Earth Observations
(NEO): Sea Surface Temperature Heat Water August 3, 2023JPEGThe Barents Sea is a shallow part
of the Arctic Ocean squeezed between the coastline of northern Russia, Scandinavia, and several

islands to the north. Microscopic forms of phytoplankton thrive in its nutrient-rich waters,
feeding invertebrates and small crustaceans that sustain an abundance of fish, seabirds, and
mammals.Individual phytoplankton are too small to be visible to the naked eye, but huge numbers
of them together can change the color of the ocean over hundreds—or even thousands—of kilometers.
These “blooms” in the Barents Sea can be hard to observe with optical imagers because it is

among the cloudiest places in the world. However, on August 3, 2023, a break in the clouds
offered a spectacular view of a bloom in the waters north of the Scandinavian and Kola peninsulas.
The image above was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS)
on NASA’s Terra satellite.Many phytoplankton species live in the cool waters of the Barents
Sea, but the milky blue color in this image suggests that the bloom contains coccolithophores,

microscopic plankton plated with white calcium carbonate. In this case, the species is likely
Emiliana huxleyi, whose blooms tend to be triggered by high light levels during the around-the-clock
daylight of Arctic summers. Other colors in the scene may come from sediment or other species
of phytoplankton, particularly diatoms.The Barents Sea usually has two major bloom seasons
each year, with diatoms peaking in May and June, then giving way to coccolithophores by August

as certain nutrients run out and waters grow warmer and more layered. As the climate changes,
increasing amounts of warm water from the Atlantic Ocean are flowing into the Barents Sea
and reducing the amount of sea ice. As these changes play out, scientists are using satellites
to track how phytoplankton populations are responding.One group of researchers observed large
shifts in the location of summer coccolithophore blooms to the northeast between 2002 and

2018. They also identified an increasing presence of Phaeocystis pouchetii, a type of phytoplankton
normally found in warmer waters that can form gelatinous colonies millimeters in diameter.
The effect that such changes might have on the ecosystem is a topic of ongoing research.NASA
Earth Observatory image by Michala Garrison, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview.
Story by Adam Voiland.View this area in EO ExplorerA break in the clouds offered a glimpse

of phytoplankton north of Norway, Finland, and Russia.Image of the Day for August 5, 2023
Image of the Day Water Water Color View more Images of the Day:Floating, plant-like organisms
reproduce abundantly when there are sufficient nutrients, sunlight, and water conditions.
Extreme blooms of certain species can become harmful to marine animals and humans.In July
2016, phytoplankton in the Barents Sea turned the surface waters milky blue. Life Water Water

Color Acquired September 10, 2011, this natural-color image shows a persistent phytoplankton
bloom in the Barents Sea. Life Water Water Color Acquired August 24, 2012, this natural-color
image shows a profusion of peacock hues created by a phytoplankton bloom in the Barents Sea.

The moisture trapped in the soil affects a lot more than the health of
crops and trees. Look at natural--color satellite images and it becomes
clear that most of the water on Earth (about 97 percent) is stored in
the oceans. Next you might notice some on the land: liquid water fills
lakes and rivers, while frozen water blankets the poles and
mountaintops. In the atmosphere, water is visible in the countless tiny
droplets that compose the clouds, though there is plenty of moisture
even in cloud-free skies.

Soil moisture has many expressions and influences in Earth's climate,
from evaporation to freezing and thawing ice to droughts and floods.
(Photos used under a Creative Commons license, courtesy of Guido
Appenzeller (top left), TREEAID (bottom left), and Mike Rosenberg (top
right). NASA Earth Observatory image (bottom right) by Joshua Stevens,
using Landsat data from the U.S. Geological Survey.)

Not immediately visible, however, is the water residing in the soil.
This water does not appear brilliantly blue or white, like the oceans or
ice. In fact, it is hard to spot in natural-color satellite images.

Compared to the amount of water stored elsewhere on the planet, the
amount in the soil is minuscule. But that small volume has great
significance. It can affect when, where, and what a farmer will plant.
It can influence the weather. And at high northern latitudes, soil
moisture has serious implications for global climate.

For all of these reasons, researchers have developed satellite
instruments to measure the water hidden between soil particles. The
instruments are either active or passive.

Active radar sensors transmit microwave radiation toward the ground and
measure the echoes. Depending on the moisture content, the reflected
signal will "look" different---information scientists then use to derive
the amount of soil moisture. (One such sensor flies on the Metop
satellites operated by the European Organization for the Exploitation of
Meteorological Satellites.) The radar approach allows scientists to
measure moisture in very specific areas (high resolution), but it is
less accurate than other approaches.

"Passive radiometers detect microwave wavelengths of light that are
naturally emitted by the soil. Because the signal varies with wetness,
scientists can use the information to estimate the amount of moisture in
the top few inches of soil. These measurements give better estimates of
the amount of water, but over a broader area (coarse spatial resolution)
than active radar. The European Space Agency has flown a passive
radiometer on the Soil Moisture and Ocean Salinity (SMOS) mission since
2009, and NASA put them on the Aqua (2002) and Aquarius (2011)
satellites. NASA's Soil Moisture Active Passive (SMAP) satellite was
launched in January 2015 and carries both a radiometer and radar.
However, the radar stopped transmitting data a few months after launch.

The Soil Moisture Active Passive (SMAP) satellite can observe global
soil moisture daily at a 36-kilometer resolution. (NASA Earth
Observatory map by Joshua Stevens, using data courtesy of JPL and the
SMAP science team.)

All of these platforms, combined with insights from ground-based
sensors, contribute to a growing record of global soil moisture. The
goal is to establish a standardized set of measurements for the entire
planet so that everyone from meteorologists to climate modelers can
track the movement of this small but vital reservoir of water.

The most obvious users of soil moisture data are farmers and ranchers.
There's more to it, however, than the simple fact that plants need water
to grow. Knowing something about the moisture in the soil is important
before, during, and after the growing season. For example, will mud
prevent a tractor from safely driving across the fields? How much water
will fruits, nuts, and vegetables have available at each stage of
growth, from germination through harvest? What is the forecast for crop
yields around the world? How will the amount of moisture and
agricultural output affect trade policy and food aid?

Ground-based sensors can monitor soil moisture over small areas,
typically less than one square meter. To find out what is happening over
larger areas, researchers in several U.S. states have patched together a
network of sensors. In Oklahoma, for example, a network to monitor
weather and climate parameters (including soil moisture) was conceived
after a disastrous flood struck Tulsa in 1984. Interest in this type of
network for agricultural purposes also arose in Stillwater. The result
was an environmental monitoring network called Mesonet, which in 1996
started to include soil moisture sensors.

Today, more than 100 stations across Oklahoma are making measurements at
various soil depths down to 60 centimeters (24 inches). Sensors record
the temperature during and after a imparting a pulse of heat; the amount
of water in the soil can then be inferred from the temperature change.
(Other ground-based methods involve neutron scattering or soil coring.)
Data from these sensors, updated every 30 minutes, can help farmers
quickly figure out where there is inadequate moisture in their fields.

Mesonet is just one of 31 networks and 1,479 stations in North America.
But, in situ networks do not cover all areas of the United States, and
certainly not the planet.

Nearly 1,500 stations track soil moisture in locations across the United
States. As an example, the plot shows data from the Coastal Sage UCI
station (California). As the map shows, the network is relatively sparse
for the size of the nation. (NASA Earth Observatory map and chart by
Joshua Stevens, using data from the TAMU North American Soil Moisture
Database.)

To fill in the gaps, some scientists estimate global soil moisture by
running computer models loaded with precipitation, temperature, and
humidity data. Gathering all of the data to run such models can take as
long as two to three months, which makes real-time applications
impossible.

"What we really want is soil moisture information that can be used to
understand how plants are growing and what's going on in the atmosphere
right now," said Susan Moran, a hydrologist with USDA's Agricultural
Research Service and chair of the SMAP Applications Working Group. "We
have to get soil moisture information to the agriculture community, and
the only way to do that is from satellites."

With the recent satellite missions, Moran and colleagues have been
learning more about how soil moisture affects plant growth and
agricultural productivity, especially during conditions of water
shortage and drought. For instance, she notes there have been drier and
longer droughts than the one currently parching the western U.S., but
none that have been so hot. The combination of heat and the lack of
water is driving soil moisture to unprecedented deficits.

"Data from SMAP will make a giant difference for my work," she said. "We
have already looked at five years of data from SMOS; add SMAP onto that
and we begin to get a good time series of global soil moisture to help
us figure out where vegetation has a high risk of mortality."

Soil moisture has an obvious, visible effect on the landscape. The
high-profile examples are droughts and floods. But the water in the soil
has a more subtle, yet equally important role in day-to-day weather.

Soil moisture forms a vast, thin, and mostly out-of-sight reservoir of
water that accumulates in the root zone of plants. The water is released
to the atmosphere through evaporation and plant transpiration. Averaged
globally, this evapotranspiration contributes to more than 60 percent of
the precipitation that falls over land each year.

Today, satellites can measure soil moisture globally and quickly.
Saturated soils in the map above---measured by SMAP on October 5,
2015---were the result of intense rains that caused flooding in the
southeastern United States. (NASA Earth Observatory map by Joshua
Stevens, using soil moisture data courtesy of JPL and the SMAP science
team.)

"The first time we were struck by the importance of soil moisture for
weather forecasts was in July 1993," said Patricia de Rosnay, a
researcher at the European Centre for Medium-Range Weather Forecasts
(ECMWF). During the first six months of that year, extreme amounts of
rain and snow fell on the central United States. Yet the existing
weather models were not accounting for the storage and evaporation of
all of that water. They could not see how the water on the land was
feeding back into the weather patterns to make the deluge more extreme.
By July 1993, the Upper Mississippi River faced its worst flooding on
record.

July 1993 also happened to be the same month that ECMWF scientists began
testing a new weather forecast model. Their model accounted for soil
moisture in the root zone, allowing researchers to see how the soil
sustained a high level of evaporation and fed the extreme rainfall
event. The new model had produced a closer representation of reality.

The strength of the connection between soil moisture and the weather is
not the same everywhere. According to NASA scientist Randy Koster, there
are hot spots---about 10 percent of Earth's surface where the amount of
soil moisture plays a more critical role in the weather.

Water that evaporates from Earth's surface is linked to the formation of
clouds and rainfall. In dry areas, variations in the amount of
evaporation are too small to have much of an effect on the atmosphere.
In humid regions, particularly the tropics, changes in soil moisture do
not matter much for evaporation because it is limited by the amount of
water that the atmosphere can hold.

Landsat 8 acquired this image N'Djamena, Chad, on October 20, 2015. The
city sits along the Logone River and within the African Sahel. As
pictured here after the rainy season, the river's saturated banks are
surrounded by a dry, sandy landscape. (NASA Earth Observatory image by
Joshua Stevens, using Landsat data from the U.S. Geological Survey.)

The soil moisture hot spots are areas that are neither too dry nor too
wet. They are located in the transition zones between dry and wet
areas---places that have suitably high evaporation that is more
dependent on moisture on the ground than in the atmosphere. The
Midwestern United States is one of those hot spots. So, too, are
northern India and the African Sahel.

Better estimates of soil moisture in weather models will not necessarily
make for perfect long-range forecasts. Randomness in the variables that
cause weather will always hinder the accuracy beyond a few days. But
with better information on the thin reservoir in the soil, forecasters
can tip the scales further in favor of getting weather prediction right.

In the planet's highest northern latitudes, even the water in the soil
is locked away as ice, making it mostly inaccessible to plants. But just
a short distance to the south, in the boreal areas of Alaska, Canada,
Siberia, and Scandinavia, the landscape comes alive each year after the
spring thaw.

The transition is relatively rapid, occurring over just a few weeks, and
coincides with increasing sunlight and spring snowmelt. Rapid warming
releases liquid water. As liquid water becomes more readily available,
plant and animal activity are energized. The land greens up, and animals
return to graze.

"I'm always impressed by how rapidly northern landscapes transition from
frozen and dormant conditions in the winter to a rapid burst of life and
activity in the spring," said John Kimball, a scientist at the
University of Montana.

The transition between frozen and thawed land is something researchers
have observed for more than 30 years with satellites. The Nimbus-7
Pathfinder, the Defense Meteorological Satellite Program (DMSP)
satellites, and Aqua all have carried passive microwave radiometers.
They detect the microwave energy coming from the Earth's surface, which
will have different characteristics depending on whether the soil is
frozen or thawed. When surface water and soil moisture is locked away as
ice, this frozen landscape looks like a desert to a microwave sensor.
Thawed landscapes look comparatively wet, so this large contrast is the
basis for something called a freeze-thaw measurement.

Across a year, the ice and frozen lands advance and retreat in the high
northern and southern latitudes. (NASA Earth Observatory image by Joshua
Stevens, using NASA's Blue Marble data.)

Kimball and colleagues have mined 30 years of freeze-thaw patterns from
the satellite record. In a paper published in 2012, the researchers
showed that soils in the Northern Hemisphere thawed for as many as 7.5
days more in 2008 than they did in 1979. The change was primarily driven
by an earlier start to the spring thaw and coincided with measureable
warming in the region.

"This was a real eye-opener to me," Kimball said. "We found that the
earlier spring-thaw was driving widespread increases in northern growing
seasons." The start and the length of the growing season have
implications for how much carbon is exchanged between the land and
atmosphere.

Each year, half of all global carbon emissions are removed from the
atmosphere by natural processes on the surface. It is sequestered
somewhere on land, and a large amount of that carbon is stored at high
latitudes. According to scientists at the Woods Hole Research Center,
the boreal region covers about 15 percent of the global land surface,
yet holds more than 30 percent of all carbon contained on land.

A longer growing season in the north could make vegetation a more
important "sink," removing carbon dioxide from the atmosphere and
storing it in forest biomass, dead organic matter, and the soil. But
those boreal lands also could become a carbon source though burning,
decay, and thawing soil. Currently, the region is thought by many to be
a net sink, absorbing more carbon than it releases. But how might
thawing soils affect that balance?

The answer is complicated by the fact that the timing of the thaw can
vary dramatically over a small area. Sunlight sweeps over the landscape
at a low angle, so areas with even the slightest rolling topography can
be cast in either shade or sunlight. South-facing slopes thaw first. And
just a few extra weeks of thawing time can have a huge impact on plant
growth.

Another complication in the carbon equation is permafrost. Even where
the top layer of soil has thawed, there is often a long-term frozen
layer below. This frozen layer locks up carbon so that it cannot
decompose. But as seasonal thaws reach greater soil depths, more organic
matter can decompose and get flushed out into the atmosphere by streams
or degassing into the atmosphere. "There is debate as to how stable that
soil will be with continued global warming," Kimball says.

But progress is being made. Freeze-thaw monitoring, according to
Kimball, has made a major advance thanks to the development of
well-calibrated, long-term satellite soil moisture records. As those
observations continue, and as they encompass more of the planet, it
stands to reason that our understanding of the entire water cycle will
improve.

Soil moisture has an obvious, visible effect on the landscape. The
high-profile examples are droughts and floods. But the water in the soil
has a more subtle, yet equally important role in day-to-day weather.

Soil moisture forms a vast, thin, and mostly out-of-sight reservoir of
water that accumulates in the root zone of plants. The water is released
to the atmosphere through evaporation and plant transpiration. Averaged
globally, this evapotranspiration contributes to more than 60 percent of
the precipitation that falls over land each year.

"The first time we were struck by the importance of soil moisture for
weather forecasts was in July 1993," said Patricia de Rosnay, a
researcher at the European Centre for Medium-Range Weather Forecasts
(ECMWF). During the first six months of that year, extreme amounts of
rain and snow fell on the central United States. Yet the existing
weather models were not accounting for the storage and evaporation of
all of that water. They could not see how the water on the land was
feeding back into the weather patterns to make the deluge more extreme.
By July 1993, the Upper Mississippi River faced its worst flooding on
record.

July 1993 also happened to be the same month that ECMWF scientists began
testing a new weather forecast model. Their model accounted for soil
moisture in the root zone, allowing researchers to see how the soil
sustained a high level of evaporation and fed the extreme rainfall
event. The new model had produced a closer representation of reality.

The strength of the connection between soil moisture and the weather is
not the same everywhere. According to NASA scientist Randy Koster, there
are hot spots---about 10 percent of Earth's surface where the amount of
soil moisture plays a more critical role in the weather.

Water that evaporates from Earth's surface is linked to the formation of
clouds and rainfall. In dry areas, variations in the amount of
evaporation are too small to have much of an effect on the atmosphere.
In humid regions, particularly the tropics, changes in soil moisture do
not matter much for evaporation because it is limited by the amount of
water that the atmosphere can hold.

The soil moisture hot spots are areas that are neither too dry nor too
wet. They are located in the transition zones between dry and wet
areas---places that have suitably high evaporation that is more
dependent on moisture on the ground than in the atmosphere. The
Midwestern United States is one of those hot spots. So, too, are
northern India and the African Sahel.

Better estimates of soil moisture in weather models will not necessarily
make for perfect long-range forecasts. Randomness in the variables that
cause weather will always hinder the accuracy beyond a few days. But
with better information on the thin reservoir in the soil, forecasters
can tip the scales further in favor of getting weather prediction right.

Remotely sensed biomass carbon density maps are widely used for myriad
scientific and policy applications, but all remain limited in scope.
They often only represent a single vegetation

type and rarely account for carbon stocks in belowground biomass. To
date, no global product integrates these disparate estimates into an
all-encompassing map at a scale appropriate

for many modelling or decision-making applications. We developed an
approach for harmonizing vegetation-specific maps of both above and
belowground biomass into a single, comprehensive

representation of each. We overlaid input maps and allocated their
estimates in proportion to the relative spatial extent of each
vegetation type using ancillary maps of percent tree

cover and landcover, and a rule-based decision schema. The resulting
maps consistently and seamlessly report biomass carbon density estimates
across a wide range of vegetation types

in 2010 with quantified uncertainty. They do so for the globe at an
unprecedented 300-meter spatial resolution and can be used to more
holistically account for diverse vegetation carbon

stocks in global analyses and greenhouse gas inventories. Background &
Summary Terrestrial ecosystems store vast quantities of carbon (C) in
aboveground and belowground biomass1. At

any point in time, these stocks represent a dynamic balance between the
C gains of growth and C losses from death, decay and combustion. Maps of
biomass are routinely used for benchmarking

biophysical models2,3,4, estimating C cycle effects of disturbance5,6,7,
and assessing biogeographical patterns and ecosystem services8,9,10,11.
They are also critical for assessing

climate change drivers, impacts, and solutions, and factor prominently
in policies like Reducing Emissions from Deforestation and Forest
Degradation (REDD+) and C offset schemes12,13,14.

Numerous methods have been used to map biomass C stocks but their
derivatives often remain limited in either scope or extent12,15. There
thus remains a critical need for a globally

harmonized, integrative map that comprehensively reports biomass C
across a wide range of vegetation types. Most existing maps of
aboveground biomass (AGB) and the carbon it contains

(AGBC) are produced from statistical or data-driven methods relating
field-measured or field-estimated biomass densities and spaceborne
optical and/or radar imagery12,15,16. They largely

focus on the AGB of trees, particularly those in tropical landscapes
where forests store the majority of the region's biotic C in aboveground
plant matter. Land cover maps are often

used to isolate forests from other landcover types where the predictive
model may not be appropriate such that forest AGB maps intentionally
omit AGB stocks in non-forest vegetation

like shrublands, grasslands, and croplands, as well as the AGB of trees
located within the mapped extent of these excluded landcovers17.
Non-forest AGB has also been mapped to some

extent using similar approaches but these maps are also routinely masked
to the geographic extent of their focal landcover18,19,20,21. To date,
there has been no rigorous attempt to

harmonize and integrate these landcover-specific, remotely sensed
products into a single comprehensive and temporally consistent map of C
in all living biomass. Maps of belowground

biomass (BGB) and carbon density (BGBC) are far less common than those
of AGB because BGB cannot be readily observed from space or airborne
sensors. Consequently, BGB is often inferred

from taxa-, region-, and/or climate-specific "root-to-shoot" ratios that
relate the quantity of BGB to that of AGB22,23,24. These ratios can be
used to map BGB by spatially applying

them to AGB estimates using maps of their respective strata5. In recent
years, more sophisticated regression-based methods have been developed
to predict root-to-shoot ratios of some

landcover types based on covariance with other biophysical and/or
ecological factors25,26. When applied spatially, these methods can allow
for more continuous estimates of local BGB5,27.

Like AGBC, though, few attempts have been made to comprehensively map
BGBC for the globe. Despite the myriad of emerging mapping methods and
products, to date, the Intergovernmental

Panel on Climate Change (IPCC) Tier-1 maps by Ruesch and Gibbs28 remains
the primary source of global AGBC and BGBC estimates that transcend
individual landcover types. These maps,

which represents the year 2000, were produced prior to the relatively
recent explosion of satellite-based AGB maps and they therefore rely on
an alternative mapping technique called

"stratify and multiply"15, which assigns landcover-specific biomass
estimates or "defaults" (often derived from field measurements or
literature reviews) to the corresponding classified

grid cells of a chosen landcover map12. While this approach yields a
comprehensive wall-to-wall product, it can fail to capture finer-scale
spatial patterns often evident in the field

and in many satellite-based products12,15. The accuracy of these maps is
also tightly coupled to the quality and availability of field
measurements29 and the thematic accuracy and

discontinuity of the chosen landcover map. Given the wealth of
landcover-specific satellite based AGB maps, a new harmonization method
akin to "stratify and multiply" is needed to

merge the validated spatial detail of landcover-specific remotely sensed
biomass maps into a single, globally harmonized product. We developed
such an approach by which we (i) overlay

distinct satellite-based biomass maps and (ii) proportionately allocate
their estimates to each grid cell ("overlay and allocate").
Specifically, we overlay continental-to-global scale

remotely sensed maps of landcover-specific biomass C density and then
allocate fractional contributions of each to a given grid cell using
additional maps of percent tree cover, thematic

landcover and a rule-based decision tree. We implement the new approach
here using temporally consistent maps of AGBC as well as matching
derived maps of BGBC to generate separate

harmonized maps of AGBC and BGBC densities. In addition, we generate
associated uncertainty layers by propagating the prediction error of
each input dataset. The resulting global maps

consistently represent biomass C and associated uncertainty across a
broad range of vegetation in the year 2010 at an unprecedented 300 meter
(m) spatial resolution. Our harmonization

approach (Fig. 1) relies on independent, landcover-specific biomass maps
and ancillary layers, which we compiled from the published literature
(Table 1). When published maps did not

represent our epoch of interest (i.e. grasslands and croplands) or did
not completely cover the necessary spatial extent (i.e. tundra
vegetation), we used the predictive model reported

with the respective map to generate an updated version that met our
spatial and temporal requirements. We then used landcover specific
root-to-shoot relationships to generate matching

BGBC maps for each of the input AGBC maps before implementing the
harmonization procedure. Below we describe, in detail, the methodologies
used for mapping AGBC and BGBC of each landcover

type and the procedure used to integrate them. Woody tree biomass Since
the first remotely sensed woody AGB maps were published in the early
1990s, the number of available products

has grown at an extraordinary pace16 and it can thus be challenging to
determine which product is best suited for a given application. For our
purposes, we relied on the GlobBiomass

AGB density map30 as our primary source of woody AGB estimates due to
its precision, timestamp, spatial resolution, and error quantification.
It was produced using a combination of

spaceborne optical and synthetic aperture radar (SAR) imagery and
represents the year 2010 at a 100 m spatial resolution -- making it the
most contemporary global woody AGB currently

available and the only such map available for that year. Moreover,
GlobBiomass aims to minimize prediction uncertainty to less than 30% and
a recent study suggests that it has high

fidelity for fine-scale applications31. The GlobBiomass product was
produced by first mapping the growing stock volume (GSV; i.e. stem
volume) of living trees, defined following Food

and Agriculture Organization (FAO) guidelines32 as those having a
diameter at breast height (DBH) greater than 10 centimeters (cm). AGB
density was then determined from GSV by applying

spatialized biomass expansion factors (BEFs) and wood density estimates.
These factors were mapped using machine learning methods trained from a
suite of plant morphological databases

that compile thousands of field measurements from around the globe33.
The resulting AGB estimates represent biomass in the living structures
(stems, branches, bark, twigs) of trees

with a DBH greater than 10 cm. This definition may thereby overlook AGB
of smaller trees and/or shrubs common to many global regions. Unlike
other maps, though, the GlobBiomass product

employs a subpixel masking procedure that retains AGB estimates in 100 m
grid cells in which any amount of tree cover was detected in finer
resolution (30 m) imagery34. This unique

procedure retains AGB estimates in tree-sparse regions like savannahs,
grasslands, croplands, and agroforestry systems where AGB is often
overlooked17, as well as in forest plantations.

The GlobBiomass product is the only global map that also includes a
dedicated uncertainty layer reporting the standard error of prediction.
We used this layer to propagate uncertainty

when converting AGB to AGBC density, modelling BGBC, and integrating
with C density estimates of other vegetation types. Bouvet et al.35 --
some of whom were also participants of the

GlobBiomass project -- independently produced a separate AGB density map
for African savannahs, shrublands and dry woodlands circa 2010 at 25 m
spatial resolution35 (hereafter "Bouvet

map"), which we included in our harmonized product to begin to address
the GlobBiomass map's potential omission of small trees and shrubs that
do not meet the FAO definition of woody

AGB. This continental map of Africa is based on a predictive model that
directly relates spaceborne L-band SAR imagery -- an indirect measure of
vegetation structure that is sensitive

to low biomass densities36 -- with region-specific, field-measured AGB.
Field measurements (n = 144 sites) were compiled from 7 different
sampling campaigns -- each specifically seeking

training data for biomass remote sensing -- that encompassed 8 different
countries35. The resulting map is not constrained by the FAO tree
definition and is masked to exclude grid cells

in which predicted AGB exceeds 85 megagrams dry mater per hectare (Mg
ha−1) -- the threshold at which the SAR-biomass relationship saturates.
To avoid extraneous prediction, it further

excludes areas identified as "broadleaved evergreen closed-to-open
forest", "flooded forests", "urban areas" and "water bodies" by the
European Space Agency's Climate Change Initiative

(CCI) Landcover 2010 map37 and as "bare areas" in the Global Land Cover
      (GLC) 2000 map38. While the Bouvet map is not natively accompanied
      by an uncertainty layer, its authors provided

us with an analytic expression of its uncertainty (SE; standard error of
prediction) as a function of estimated AGB (Eq. 1) which we used to
generate an uncertainty layer for subsequent

error propagation. We combined the GlobBiomass and Bouvet products to
generate a single woody biomass map by first upscaling each map
separately to a matching 300 m spatial resolution

using an area-weighted average to aggregate grid cells, and then
assigning the Bouvet estimate to all overlapping grid cells, except
those identified by the CCI Landcover 2010 map

as closed or flooded forest types (Online-only Table 1) which were not
within the dryland domain of the Bouvet map. While more complex
harmonization procedures based on various averaging

techniques have been used by others39,40, their fidelity remains unclear
since they fail to explicitly identify and reconcile the underlying
source of the inputs' discrepancies41.

We thus opted to use a more transparent ruled-based approach when
combining these two woody biomass maps, which allows users to easily
identify the source of a grid cell's woody biomass

estimate. Given the local specificity of the training data used to
produce the Bouvet map, we chose to prioritize its predictions over
those of the GlobBiomass product when within

its domain. In areas of overlap, the Bouvet map values tend to be lower
in moist regions and higher in dryer regions (Fig. 2), though, where
used, these differences rarely exceed ±25

megagrams C per hectare (MgC ha−1). We then converted all woody AGB
estimates to AGBC by mapping climate and phylogeny-specific biomass C
concentrations from Martin et al.42. Climate

zones were delineated by aggregating classes of the Köppen-Gieger
classification43 (Table 2) to match those of Martin et al.42.
Phylogenetic classes (angiosperm, gymnosperm and mixed/ambiguous)

were subsequently delineated within each of these zones using aggregated
classes of the CCI Landcover 2010 map (Online-only Table 1). Martin et
al.42 only report values for angiosperms

and gymnosperms so grid cells with a mixed or ambiguous phylogeny were
assigned the average of the angiosperm and gymnosperm values and the
standard error of this value was calculated

from their pooled variance. Due to residual classification error in the
aggregated phylogenetic classes, we weighted the phylogeny-specific C
concentration within each climate zone

by the binary probability of correctly mapping that phylogeny where,
within each climate zone, μc is the mean probability-weighted C
concentration of the most probable phylogeny, μm

is the mean C concentration of that phylogeny from Martin et al.42, pm
is the user's accuracy of that phylogeny's classification (Table 3), and
μn and μo are the mean C concentrations

of the remain phylogenetic classes from Martin et al.42. Standard error
estimates for these C concentrations were similarly weighted using
summation in quadrature where is the probability-weighted

standard error of the most probable phylogeny's C concentration and and
are the standard errors of the respective phylogeny-specific C
concentrations from Martin et al.42. Probability-weighted

C concentrations used are reported in Table. Mapped,
probability-weighted C estimates were then arithmetically applied to AGB
estimates. Uncertainty associated with this correction

was propagated using summation in quadrature of the general form (Eq. 4)
is the uncertainty of μf, and , are the respective uncertainty estimates
of the dependent parameters (standard

error unless otherwise noted). Here, μf, is the estimated AGBC of a
given grid cell, and is the product of its woody AGB estimate, and its
corresponding C concentration. Tundra vegetation

biomass The tundra and portions of the boreal biome are characterized by
sparse trees and dwarf woody shrubs as well as herbaceous cover that are
not included in the GlobBiomass definition

of biomass. AGB density of these classes has been collectively mapped by
Berner et al.18,45 for the North Slope of Alaska from annual Landsat
imagery composites of the normalized difference

vegetation index (NDVI) and a non-linear regression-based model trained
from field measurements of peak AGB that were collected from the
published literature (n = 28 sites). Berner

et al.18 note that while these field measurements did not constitute a
random or systematic sample, they did encompass a broad range of tundra
plant communities. In the absence of

a global map and due the sparsity of high quality Landsat imagery at
high latitudes, we extended this model to the pan-Arctic and
circumboreal regions using NDVI composites created

from daily 250 m MODIS Aqua and Terra surface reflectance images46,47
that were cloud masked and numerically calibrated to Landsat ETM
reflectance -- upon which the tundra model is

based -- using globally derived conversion coefficients48. We generated
six separate 80th percentile NDVI composites circa 2010 -- one for each
of the MODIS missions (Aqua and Terra)

in 2009, 2010 and 2011 -- following Berner et al.18. We chose to use
three years of imagery (circa 2010) rather than just one (2010) to
account for the potential influence that cloud

masking may exert upon estimates of the 80th NDVI percentile in a single
year. We then applied the tundra AGB model to each composite, converted
AGB estimates to AGBC by assuming a

biomass C fraction of 49.2% (SE = 0.8%)42 and generated error layers for
each composite from the reported errors of the AGB regression
coefficients and the biomass C conversion factor

using summation in quadrature as generally described above (Eq. 4). A
single composite of tundra AGBC circa 2010 was then created as the
pixelwise mean of all six composites. We also

generated a complementary uncertainty layer representing the cumulative
standard error of prediction, calculated as the pixelwise root mean of
the squared error images in accordance

with summation in quadrature. Both maps were upscaled from their native
250 m spatial resolution to a 300 m spatial resolution using an area
weighted aggregation procedure, whereby

pixels of the 300 m biomass layer was calculated as the area weighted
average of contained 250 m grid cells, and the uncertainty layer was
calculated -- using summation in quadrature

-- as the root area-weighted average of the contained grid cells
squared. Grassland biomass Grassland AGBC density was modelled directly
from maximum annual NDVI composites using a

non-linear regression-based model developed by Xia et al.19 for mapping
at the global scale. This model was trained by relating maximum annual
NDVI as measured by the spaceborne Advanced

Very High-Resolution Radiometer (AVHRR) sensor to globally distributed
field measurements of grassland AGBC that were compiled from the
published literature (81 sites for a total of

158 site-years). Like the tundra biomass training data, these samples
did not constitute a random or systematic sample but do encompass a
comprehensive range of global grassland communities.

Given the inevitable co-occurrence of trees in the AVHRR sensor's 8 km
resolution pixels upon which the model is trained, it's predictions of
grassland AGBC are relatively insensitive

to the effects of co-occurring tree cover. We thereby assume that its
predictions for grid cells containing partial tree cover represent the
expected herbaceous AGBC density in the

absence of those trees. Maximum model predicted AGBC (NDVI = 1) is 2.3
MgC ha−1 which is comparable to the upper quartile of herbaceous AGBC
estimates from global grasslands49 and

suggests that our assumption will not lead to an exaggerated estimation.
For partially wooded grid cells, we used modelled grassland AGBC density
to represent that associated with

the herbaceous fraction of the grid cell in a manner similar to Zomer et
al.17 as described below (See "Harmonizing Biomass Carbon Maps"). We
applied the grassland AGBC model to all

grid cells of maximum annual NDVI composites produced from finer
resolution 16-day (250 m) MODIS NDVI imagery composites circa 201050,51.
Here again, three years of imagery were used

to account for potential idiosyncrasies in a single year's NDVI
composites resulting from annual data availability and quality. As with
AGB of tundra vegetation, annual composites

(2009--2011) were constructed separately from cloud-masked imagery
collected by both MODIS missions (Aqua and Terra; n = 6) and then
numerically calibrated to AVHRR reflectance using

globally derived conversion coefficients specific to areas of herbaceous
cover52. We then applied the AGBC model to each of these composites and
estimated error for each composite

from both the AVHRR calibration (standard deviation approximated from
the 95% confidence interval of the calibration scalar) and the AGBC
model (relative RMSE) using summation in quadrature.

A single map of grassland AGBC circa 2010 was then created as the
pixelwise mean of all six composites and an associated error layer was
created as the pixelwise root mean of the squared

error images. Both maps were aggregated from their original 250 m
resolution to 300 m to facilitate harmonization using the area-weighted
procedure described previously for woody and

tundra vegetation (see section 1.2). Cropland biomass Prior to harvest,
cropland biomass can also represent a sizable terrestrial C stock. In
annually harvested cropping systems, the

maximum standing biomass of these crops can be inferred from annual net
primary productivity (ANPP). While spaceborne ANPP products exist, they
generally perform poorly in croplands53,54.

Instead, cropland ANPP is more commonly derived from crop
yields20,21,53. We used globally gridded, crop-specific yields of 70
annually harvested herbaceous commodity crops circa 2000

by Monfreda et al.20 -- the only year in which these data were
available. These maps were produced by spatially disaggregating
crop-yield statistics for thousands of globally distributed

administrative units throughout the full extent of a satellite-based
cropland map20. These maps were combined with crop-specific parameters
(Online-only Table 2) to globally map AGBC

as aboveground ANPP for each crop following the method of Wolf et al.21.
This method can be simplified as (Eq. 5) where y is the crop's yield (Mg
ha−1), ω is the dry matter fraction

of its harvested biomass, h is its harvest index (fraction of total AGB
collected at harvest) and c is the carbon content fraction of its
harvested dry mass. This simplification assumes,

following Wolf et al.21, that 2.5% of all harvested biomass is lost
between the field and farmgate and that unharvested residue and root
mass is 44% C. Total cropland AGBC density

was then calculated as the harvested-area-weighted average of all
crop-specific AGBC estimates within a given grid cell. Since multiple
harvests in a single year can confound inference

of maximum AGBC from ANPP, we further determined the harvest frequency
(f) of each grid cell by dividing a cell's total harvested area (sum of
the harvested area of each crop reported

within a given grid cell) by its absolute cropland extent as reported in
a complementary map by Ramankutty et al.55. If f was greater than one,
multiple harvests were assumed to have

occurred and AGBC was divided by f to ensure that AGBC estimates did not
exceed the maximum standing biomass density. Since the yields of many
crops and, by association, their biomass

have changed considerably since 200056,57, we calibrated our circa 2000
AGBC estimates to the year 2010 using local rates of annual ANPP change
(MgC ha−1 yr−1) derived as the Theil-Sen

slope estimator -- a non-parametric estimator that is relatively
insensitive to outliers -- of the full MODIS Terra ANPP timeseries
(2000--2015)58. Total ANPP change between 2000 and

2010 for each grid cell was calculated as ten times this annual rate of
change. Since MODIS ANPP represents C gains in both AGB and BGB, we
proportionately allocated aboveground ANPP

to AGBC using the total root-to-shoot ratio derived from the circa 2000
total crop AGBC and BGBC maps (described below). Since error estimates
were not available for the yield maps

or the crop-specific parameters used to generate the circa 2000 AGBC
map, estimated error of the circa 2010 crop AGBC map was exclusively
based on that of the 2000--2010 correction.

The error of this correction was calculated as the pixel-wise standard
deviation of bootstrapped simulations (n = 1000) in which a random
subset of years was omitted from the slope

estimator in each iteration. The 8 km resolution circa 2000 AGBC map and
error layer were resampled to 1 km to match the resolution of MODIS ANPP
using the bilinear method prior to

ANPP correction and then further resampled to 300 m to facilitate
harmonization. Woody crops like fruit, nut, and palm oil plantations
were not captured using the procedure just described

and their biomass was instead assumed to be captured by the previously
described woody biomass products which retained biomass estimates in all
pixels where any amount of tree cover

was detected at the sub-pixel level (see section 1.1). Belowground
biomass carbon maps Matching maps of BGBC and associated uncertainty
were subsequently produced for each of the landcover-specific

AGBC maps using published empirical relationships. With the exception of
savannah and shrubland areas, woody BGBC was modelled from AGBC using a
multiple regression model by Reich

et al.25 that considers the phylogeny, mean annual temperature (MAT),
and regenerative origin of each wooded grid cell and that was applied
spatially using maps of each covariate in

a fashion similar to other studies5,27. Tree phylogeny (angiosperm or
gymnosperm) was determined from aggregated classes of the CCI Landcover
2010 map37 (Online-only Table 1) with

phylogenetically mixed or ambiguous classes assumed to be composed of
50% of each. MAT was taken from version 2 of the WorldClim bioclimatic
variables dataset (1970--2000) at 1 km resolution59

and resampled to 300 m using the bilinear method. Since there is not a
single global data product mapping forest management, we determined tree
origin -- whether naturally propagated

or planted -- by combining multiple data sources. These data included
(i) a global map of "Intact Forest Landscapes" (IFL) in the year 201360
(a conservative proxy of primary, naturally

regenerating forests defined as large contiguous areas with minimal
human impact), (ii) a Spatial Database of Planted Trees (SDPT) with
partial global coverage61, (iii) national statistics

reported by the FAO Global Forest Resources Assessment (FRA) on the
extent of both naturally regenerating and planted forests and woodlands
within each country in the year 201062,

total area of natural and planted trees was equal to the corresponding
FRA estimates. If the FAOSTAT-reported area of tree crops exceeded
FRA-reported planted area, the difference

was added to FRA planted total. All areas mapped as IFL were assumed to
be of natural origin and BGB was modelled as such. Likewise, besides the
exceptions noted below, all tree plantations

mapped by the SDPT were assumed to be of planted origin. In countries
where the extent of the IFL or SDPT maps fell short of the FRA/FAOSTAT
reported areas of natural or planted forests,

respectively, we estimated BGBC in the remaining, unknown-origin forest
grid cells of that country (BGBCu), as the probability-weighted average
of the planted and natural origin estimates

using Eq. 6 and are the respective BGBC estimates for a grid cell
assuming entirely planted and natural origin, respectively, and and are
the respective differences between (i) the

FRA/FAOSTAT and (ii) mapped extent of planted and natural forest within
the given grid cell's country. While the mapped extent of IFL forests
within a given country never exceeded

that country's FRA reported natural forest extent, there were infrequent
cases (n = 22 of 257) in which the mapped extent of tree plantations
exceeded the corresponding FRA/FAOSTAT

estimate of planted forest area. In these cases, we down-weighted the
BGB estimates of SDPT forests in a similar fashion such that the weight
of their planted estimate ( ) was equal

to the quotient of (i) the FRA/FAOSTAT planted area and (ii) the SDPT
extent within the country, and the weight of the natural origin estimate
applied to the SDPT extent ( ) was equal

to A BGBC error layer was then produced using summation in quadrature
from the standard error estimates of the model coefficients, the AGBC
error layer, the relative RMSE of MAT (27%),

and the derived global uncertainty of the phylogeny layer. Phylogeny
error was calculated as the Bernoulli standard deviation (δ) of the
binary probability (p) of correct classification

(i.e. "area weighted user's accuracy"44; Table 3) using Eq. 7. Since
savannahs and shrublands are underrepresented in the regression-based
model25, their BGBC was instead estimated

using static root-to-shoot ratios reported by Mokany et al.22, which are
somewhat conservative in comparison to the IPCC Tier-1 defaults23,24 put
favoured for consistency with methods

used for grasslands (see below). Error was subsequently mapped from that
of the AGBC estimates and the root-to-shoot ratios applied BGBC of
tundra vegetation was mapped from AGBC using

a univariate regression model derived by Wang et al.26 that predicts
root-to-shoot ratio as a function of MAT. We applied the model using the
WorldClim version 2 MAT map59 and propagated

error from the AGBC estimates, the relative RMSE of MAT and the standard
error of regression coefficients. Where tundra AGB exceeded 25 Mg ha−1
-- the maximum field-measured shrub biomass

reported by Berner et al.18 -- vegetation was considered to include
trees and the Reich et al.25 method described earlier for woody
vegetation was used instead. In the absence of a

continuous predictor of grassland root-to-shoot ratios, we applied
climate specific root-to-shoot ratios from Mokany et al.22 to the
corresponding climate regions of the Köppen-Gieger

classification43 (Table 2). Here, again, these ratios vary slightly from
the IPCC Tier-1 defaults23,24 but were chosen for their greater sample
size and specificity. Grassland BGBC

error was mapped from the error of the AGBC estimates and the respective
root-to-shoot ratios. Cropland BGBC was again estimated from
crop-specific yields and morphological parameters

(Online-only Table 2) following Wolf et al.21 and Eq. 8 where y is the
crop's yield (Mg ha−1), r is the root-to-shoot ratio of the crop, and h
is its harvest index. Here again we assume

that 2.5% of all harvested biomass is lost between the field and
farmgate and that root biomass is 44% C, following Wolf et al.21. BGBC
error was mapped from the error of the 2000-to-2010

ANPP correction for BGBC allocation as described above for cropland
AGBC. Harmonizing biomass carbon maps The AGBC and BGBC maps were
harmonized separately following the same general

schema (Fig. 3). Given that our harmonized woody biomass map contains
biomass estimates for grid cells in which any amount of tree cover was
detected at the subpixel level (see section

1.1), we conserved its estimates regardless of the landcover reported by
the 2010 CCI map in order to more fully account for woody biomass in
non-forested areas17. We then used the

MODIS continuous vegetation fields percent tree cover map for 201063 to
allocate additional biomass density associated with the most probable
herbaceous cover (grass or crop) to each

grid cell in quantities complementary to that of the grid cell's
fractional tree cover estimate (Eq. 9) where μT is the total biomass
estimate of a grid cell, μw is the woody biomass

estimate for the grid cell, μh is its herbaceous biomass estimate, and q
is the MODIS fractional tree cover of the grid cell. Since MODIS tree
cover estimates saturate at around 80%64,

we linearly stretched values such that 80% was treated as complete tree
cover (100%). Moreover, we acknowledge that percent cover can
realistically exceed 100% when understory cover

is considered but we were unable to reasonably determine the extent of
underlying cover from satellite imagery. As such, our approach may
underestimate the contribution of herbaceous

C stocks in densely forested grid cells. The most likely herbaceous
cover type was determined from the CCI Landcover 2010 map, which we
aggregated into two "likely herbaceous cover"

classes -- grass or crop -- based on the assumed likelihood of cropland
in each CCI class (Online-only Table 1). However, due to inherent
classification error in the native CCI Landcover

map, when determining the herbaceous biomass contribution we weighted
the relative allocation of crop and grass biomass to a given grid cell
based on the probability of correct classification

by the CCI map (i.e. "user's accuracy", Table 6) of the most probable
herbaceous class ( ) such that μh can be further expressed as (Eq. 10)
where μi is the predicted biomass of the

most probable herbaceous class, and μj is that of the less probable
class. The uncertainty of a grid cell's total AGBC or BGBC estimate ( )
was determined and mapped from that of its

components ( ) by summation in quadrature which can be simplified as
(Eq. 11) is the error of the grid cell's estimated μw, is the error of
its estimated μh, and is the error of its

q.  Here, can be further decomposed and expressed as Eq. 12 to account
    for the accuracy weighted allocation procedure expressed previously
    (Eq. 10) is the error of the estimated biomass

density of the most probable herbaceous class, is the estimated standard
deviation of that class's Bernoulli probability (p; Eq. 7), and is the
error of the estimated biomass density

of the less probable herbaceous subclass. Exceptions to the above schema
were made in the tundra and boreal biomes -- as delineated by the
RESOLVE Ecoregions 2017 biome polygons65 --

where thematic overlap was likely between the woody and tundra plant
biomass maps. A separate set of decision rules (Fig. 3) was used to
determine whether grid cells in these biomes

were to be exclusively allocated the estimate of the tundra plant map or
that of the fractional allocation procedure described above. In general,
any land in these biomes identified

as sparse landcover by the CCI landcover map (Online-only Table 1) was
assigned the tundra vegetation estimate. In addition, lands north of 60°
latitude with less than 10% tree cover

or where the tundra AGBC estimate exceeded that of the woody AGBC
estimate were also exclusively assigned the tundra vegetation estimate.
Lands north of 60° latitude not meeting these

criteria were assigned the woody value with the additional contribution
of grass. Subtle numerical artefacts emerged from the divergent
methodologies employed north and south of 60°N

latitude. These were eliminated by distance weighting grid cells within
1° of 60°N based on their linear proximity to 60°N and then averaging
estimates such that values at or north

of 61°N were exclusively based on the northern methodology, those at
60°N were the arithmetic average of the two methodologies and those at
or south of 59°N were exclusively based

on the southern methodology. This produced a seamless, globally
harmonized product that integrates the best remotely sensed estimates of
landcover-specific C density. Water bodies

identified as class "210" of the CCI 2010 landcover map were then masked
from our final products. Data Records Data layers (n = 4, Table 7) for
the maps of AGBC and BGBC density (Fig.

4)  as well as their associated uncertainty maps which represent the
    combined standard error of prediction (Fig. 5) are available as
    individual 16-bit integer rasters in GeoTiff format.

All layers are natively in a WGS84 Mercator projection with a spatial
resolution of approximately 300 m at the equator and match that of the
ESA CCI Landcover Maps37. Raster values

are in units megagrams C per hectare (MgC ha−1) and have been scaled by
a factor of ten to reduce file size. These data are accessible through
the Oak Ridge National Laboratory (ORNL)

DAAC data repository. In addition, updated and/or derived
vegetation-specific layers that were used to create our harmonized 2010
maps are

available as supplemental data on figshare67. Technical Validation Our
harmonized products rely almost exclusively upon maps and models that
have been rigorously validated by their

original producers and were often accompanied by constrained uncertainty
estimates. Throughout our harmonization procedure, we strived to
conserve the validity of each of these products

by minimizing the introduction of additional error and by tracking any
introductions, as described above, such that the final error layers
represent the cumulative uncertainty of the

inputs used. Ground truth AGB and BGB data are almost always collected
for individual landcover types. Consequently, we are unable to directly
assess the validity of our integrated

estimates beyond their relationships to individual landcover-specific
estimates and the extents to which they were modified from their
original, previously-validated form prior to

and during our harmonization procedure. Modifications to independent
biomass layers Temporal and spatial updates made to existing
landcover-specific maps of non-tree AGB resulted in

relatively small changes to their predictions. For example, we used
numerically calibrated MODIS imagery to extend the Landsat-based tundra
plant AGB model beyond its native extent

(the North Slope of Alaska) to the pan-Arctic region since neither a
comparable model nor a consistent Landsat time series were available for
this extent. We assessed the effects of

these assumptions by comparing our predictions for the North Slope with
those of the original map18 (Fig. 6a). Both positive and negative
discrepancies exist between ours and the original,

though these rarely exceed ±2 MgC ha−1 and no discernibly systematic
bias was evident. Fig. 6 figure 6 Differences between landcover-specific
AGBC estimates from the original published

maps and the modified versions used as inputs to create the 2010
harmonized global maps. Tundra vegetation AGBC (a) is compared to the
Landsat-based map of Berner et al.45 for the

north slope of Alaska after converting it to units MgC ha−1. Here, the
comparison map was subsequently aggregated to a 1 km resolution and
reprojected for visualization. Grassland

AGBC (b) is compared to the AVHRR-based map of Xia et al.19 which
represents the average estimate between 1982--2006. For visualization,
the map was aggregated to a 5 km resolution

and subsequently reprojected after being masked to MODIS IGBP grasslands
in the year 200685 following Xia et al.19. As such, this map does not
necessarily represent the spatial distribution

of grid cells in which grassland estimates were used. Cropland AGBC (c)
is compared to the original circa 2000 estimates to assess the effects
of the 2000-to-2010 correction. The map

is masked to the native extent of the combined yield maps and aggregated
to a 5 km resolution for visualization. For all maps, negative values
indicate that our circa 2010 estimates

are lower than those of the earlier maps while positive values indicate
higher estimates. Full size image Our updated map of grassland biomass
carbon in the year 2010 was similarly

made by applying the original AVHRR-based model to calibrated MODIS
imagery. This too resulted in only subtle changes to the original
biomass map (Fig. 6b) that were rarely in excess

of 0.5 MgC ha−1. In most areas, our estimates were higher than those of
Xia et al.19 who mapped the mean AGBC density between 1986 and 2006.
Most of these elevated estimates corresponded

with areas in which significant NDVI increases ("greening") have been
reported while notably lower estimates in the Argentine Monte and
Patagonian steppe biomes of southern South America,

likewise, correspond with areas of reported "browning"68,69. Both
greening and browning trends are well documented phenomena and have been
linked to climatic changes70. Moreover, we

further compared AGBC estimates from both the original Xia et al.19 map
and our 2010 update to AGBC field measurements coordinated by the
Nutrient Network that were collected from

48 sites around the world between 2007 and 200949. The RMSE (0.68 MgC
ha−1) of our updated map was 10% less that of the Xia et al. map for
sites with less than 40% tree cover. Likewise,

our 2010 estimates were virtually unbiased (bias = −0.01 MgC ha−1) in
comparison to the Xia map (bias = 0.25 MgC ha−1). While still noisy,
these results suggest that our temporal update

improved the overall accuracy of estimated grassland AGBC. Finally,
cropland biomass carbon maps were also updated from their native epoch
(2000) to 2010 using pixel-wise rates of

MODIS ANPP change over a ten-year period. While MODIS ANPP may be a poor
snapshot of crop biomass in a single year, we assumed that its relative
change over time reflects real physiological

shifts affecting the cropland C cycle. This correction also resulted in
only small differences that rarely exceeded ±2 MgC ha−1 and that,
spatially, correspond well with observed declines

in the yields of select crops that have been linked to climate
change71,72 (Fig. 6c). Nonetheless, updated global yield maps comparable
to those available for 2000 would greatly improve

our understanding of the interactions between climate change, crop
yields, and C dynamics. Belowground biomass estimates Belowground
biomass is notoriously difficult to measure, model,

and also to validate. We accounted for the reported uncertainty of
nearly every variable considered when estimating belowground biomass and
pixel-level uncertainty, but we were unable

to perform an independent validation of our harmonized estimates at the
pixel level due to a paucity of globally consistent field data. To
complete such a task, a globally orchestrated

effort to collect more BGB samples data across all vegetation types is
needed. Given this lack of data, we instead compared the estimated
uncertainty of our BGBC maps to that of our

AGBC estimates to infer the sources of any divergence (Fig. 5). As
expected, our cumulative BGBC uncertainty layer generally reveals
greater overall uncertainty than our AGBC estimates,

with BGBC uncertainty roughly twice that of AGBC throughout most of the
globe. The highest absolute uncertainty was found in biomass rich
forests. Arid woodlands, especially those

of the Sahel and eastern Namibia, generally had the greatest relative
BGBC uncertainty, though their absolute uncertainty was quite small
(generally less than 3 MgC ha−1). Here, biomass

estimates of sparse woody vegetation were primarily responsible for
heightened relative uncertainty. High relative and absolute BGBC
uncertainty were also associated with predictions

in select mountainous forests (e.g. east central Chile) as well as
forested areas in and around cities. These patterns were largely driven
by AGB uncertainty in the GlobBiomass product.

Biomass harmonization The GlobBiomass global woody AGB map produced by
Santoro et al.30 comprises the backbone of our integrated products and,
with few exceptions, remains largely

unchanged in our final AGBC map. The native version of the GlobBiomass
map is accompanied by an error layer describing the uncertainty of each
pixel's biomass estimate and this too

forms the core of our integrated uncertainty layers. In areas with tree
cover, the global average error of GlobBiomass estimates is 39 Mg ha−1
or 50% with greater relative uncertainty

in densely forested areas, along the margins of forested expanses like
farm fields and cities, and in similar areas with sparse tree cover.
Adding additional grass or crop biomass

in complementary proportion to a grid cell's tree cover often did not
exceed the estimated error of the original GlobBiomass map (Fig. 7).
Grid cells exceeding GlobBiomass's native

uncertainty comprise less than 40% of its total extent. Exceptions were
primarily found in grassland and cropland dominated regions where tree
cover was generally sparse, and, consequently,

the herbaceous biomass contribution was relatively high. Even so, the
absolute magnitude of these additions remains somewhat small (less than
2.3 MgC ha−1 for grassland and 15 MgC

ha−1 for cropland). Fig. 7 figure 7 Differences between the final
harmonized AGBC map and GlobBiomass AGBC. GlobBiomass AGB was aggregated
to a 300 m spatial resolution and converted

to C density prior to comparison. Negative values indicate areas where
the new map reports lower values than GlobBiomass while positive value
denote higher estimates. Full size image

Larger deviations from GlobBiomass were also present in areas of both
dryland Africa and the Arctic tundra biome, where we used independent
layers to estimate woody biomass. In African

drylands, GlobBiomass likely underestimates woody biomass by adopting
the conservative FAO definition (DBH \> 10 cm), which implicitly omits
the relatively small trees and shrubs that

are common to the region. The Bouvet map of Africa that we used to
supplement these estimates is not bound by this constraint, was
developed from region-specific data, and predicts

substantially higher AGB density throughout much of its extent with
comparatively high accuracy (RMSE = 17.1 Mg ha−1)35. GlobBiomass also
included sporadic biomass estimates throughout

much of the Arctic tundra biome. Trees are generally scarce throughout
this biome, which is instead dominated by dwarf shrubs and herbaceous
forbs and graminoids, so given GlobBiomass's

adherence to FAO guidelines, its predictions here may be spurious. We
thus prioritized the estimates of the independent model developed
specifically to collectively predict biomass

of both woody and herbaceous tundra vegetation. These estimates were
generally higher than GlobBiomass but agreed well with independent
validation data from North America (RMSE = 2.9

Mg ha−1)18. Comparison with the IPCC Tier-1 global biomass carbon map
While far from a perfect comparison, the only other map to
comprehensively report global biomass carbon density

for all landcover types is the IPCC Tier-1 map for the year 2000 by
Ruesch and Gibbs28. As previously described, this map was produced using
an entirely different method ("stratify

and multiply") and distinct data sources23 and represents an earlier
epoch. However, the map is widely used for myriad applications, and it
may thus be informative to assess notable

differences between it and our new products. Ruesch and Gibbs28 report
total living C stocks of 345 petagrams (PgC) in AGBC and 133 PgC in BGBC
for a total of 478 PgC, globally. Our

estimates are lower at 287 PgC and 122 PgC in global AGBC and BGBC,
respectively, for a total of 409 PgC in living global vegetation
biomass. Herbaceous biomass in our maps comprised

9.1 and 28.3 PgC of total AGBC and BGBC, respectively. Half of all
herbaceous AGBC (4.5 PgC) and roughly 6% of all herbaceous BGBC (1.7
PgC) was found in croplands. Moreover, we mapped

22.3 and 6.1 PgC, respectively, in the AGB and BGB of trees located
within the cropland extent. These trees constituted roughly 7% of all
global biomass C and are likely overlooked

by both the Ruesch and Gibbs map28 and by remotely sensed forest C maps
that are masked to forested areas. Zomer et al.17 first highlighted this
potential discrepancy in the Ruesch

and Gibbs map28 when they produced a remarkably similar estimate of 34.2
Pg of overlooked C in cropland trees using Tier-1 defaults. However,
their estimates were assumed to be in

addition to the 474 PgC originally mapped by Ruesch and Gibbs28. Here,
we suggest that the 28.4 PgC we mapped in cropland trees is already
factored into our 409 PgC total. Our AGBC

product predicts substantially less biomass C than Ruesch and Gibbs28
throughout most of the pantropical region and, to a lesser extent,
southern temperate forests (Fig. 8a). This

pattern has been noted by others comparing the Ruesch and Gibbs map28 to
other satellite-based biomass maps73 and may suggest that the IPCC
default values used to create it23 are spatially

biased. In addition, well-defined areas of high disagreement emerge in
Africa that directly correspond with the FAO boundaries of the "tropical
moist deciduous forest" ecofloristic

zone and suggest that this area, in particular, may merit critical
review. Moreover, the opposite pattern is observed in this same
ecofloristic zone throughout South America. Our map

also predicts greater AGBC throughout much of the boreal forest as well
as in African shrublands and the steppes of South America. We observed
similar, though less pronounced discrepancies,

when comparing BGBC maps (Fig. 8b). Notably, our map predicts
substantially more BGBC throughout the tundra biome -- a previously
underappreciated C stock that has recently risen to

prominance74 -- the boreal forest, African shrublands and most of South
America and Australia. However, we predict less BGBC in nearly all
rainforests (Temperate and Tropical). These

differences and their distinct spatial patterns correspond with the
vegetation strata used to make the IPCC Tier-1 map28 and suggest that
the accuracy of the "stratify and multiply"

method depends heavily upon the quality of the referenced and spatial
data considered. Inaccuracies in these data may, in turn, lead to false
geographies. Integrating, continuous spatial

estimates that better capture local and regional variation, as we have
done, may thus greatly improve our understanding of global carbon
geographies and their role in the earth system.

Congruence with IPCC Tier-2 and Tier-3 nationally reported woody carbon
stocks The error and variance between our woody biomass estimates --
when aggregated to the country level -- and

comparable totals reported in the FRA were less for comparisons made
against FRA estimates generated using higher tier IPCC methodologies
than for those based on Tier-1 approaches

(Fig. 9). Across the board for AGBC, BGBC, and total C comparisons, the
relative RMSE (RMSECV) of our estimates, when compared to estimates
generated using high tier methods, was roughly

half of that obtained from comparisons with Tier-1 estimates (Table 8).
Likewise, the coefficient of determination (R2) was greatest for
comparisons with Tier-3 estimates. For each

pool-specific comparison (AGBC, BGBC, and total C), the slopes of the
relationships between Tier-1, 2, and 3 estimates were neither
significantly different from a 1:1 relationship

nor from one another (p \> 0.05; ANCOVA). Combined, these results
suggest that our maps lead to C stock estimates congruent with those
attained from independent, higher-tier reporting

methodologies. Fig. 9 figure 9 Comparison of woody biomass density
estimates to corresponding estimates of the FAO's FRA and the USFS's
FIA. National woody AGBC totals derived from

the woody components of our harmonized maps are compared to national
totals reported in the 2015 FRA62 (a) in relation to the IPCC inventory
methodology used by each country. Likewise,

we derived woody AGBC totals for US states and compared them to the
corresponding totals reported by the 2014 FIA75 (b), a Tier-3 inventory.
We also show the additional effect of considering

non-woody C -- as is reported in our harmonized maps -- in light green.
Similar comparisons were made between our woody BGBC estimates and the
corresponding estimates of both the FRA

(c) and FIA (d). We further summed our woody AGBC and BGBC estimates and
    compared them to the total woody C stocks reported by both the
    FRA (e) and FIA (f). Full size image Table 8

Statistical comparison of woody biomass carbon totals derived from the
2010 harmonized maps and those reported by the FRA in relation to the
IPCC inventory methodology used. Full size

table To explore this association at a finer regional scale, we also
compared our woody C estimates to the United States Forest Service's
Forest Inventory Analysis75 (FIA) and found

similarly strong congruence for AGBC and Total C stocks but subtle
overestimates for BGBC (Fig. 9). The FIA is a Tier-3 inventory of woody
forest biomass C stocks that is based on

extensive and statistically rigorous field sampling and subsequent
upscaling, We used data available at the state level for the year 2014
-- again, the only year in which we could obtain

data partitioned by AGBC and BGBC. Like our FRA comparison, we found a
tight relationship between our woody AGBC totals and those reported by
the FIA (Fig. 9b; RMSECV = 25.7%, R2 =

0.960, slope = 1.10, n = 48). Our woody BGBC estimates, though, were
systematically greater than those reported by the FIA (Fig. 9d; RMSECV =
86.4%, R2 = 0.95, slope = 1.51, n = 48).

This trend has been noted by others27 and suggests that the global model
that we used to estimate woody BGBC may not be appropriate for some
finer scale applications as is foretold

by the elevated uncertainty reported in our corresponding uncertainty
layer (Fig. 5b). Our total woody C (AGBC + BGBC) estimates (Fig. 9f),
however, agreed well with the FIA (RMSECV

= 34.1%, R2 = 0.961, slope = 1.17, n = 48) and thus reflect the outsized
contribution of AGBC to the total woody C stock. When the contribution
of herbaceous C stocks is further added

to these comparisons, our stock estimates intuitively increase in rough
proportion to a state's proportional extent of herbaceous cover. The
effect of this addition is particularly

pronounced for BGBC estimates due to the large root-to-shoot ratios of
grassland vegetation. The relative congruence of our results with
higher-tier stock estimates suggests that our

maps could be used to facilitate broader adoption of higher-tier methods
among countries currently lacking the requisite data and those seeking
to better account for C in non-woody

biomass. This congruence spans a comprehensive range of biophysical
conditions and spatial scales ranging from small states to large
nations. Moreover, a recent study suggests that

the fidelity of the underlying GlobBiomass AGB map may extend to even
finer scales31. While our BGBC estimates may differ from some fine-scale
estimates (Fig. 9d), their tight agreement

with high tier BGBC totals at the national level (Fig. 9c) suggests that
they may still be well suited for many national-scale C inventories --
especially for countries lacking requisite

high tier data. Use of our maps is unlikely to introduce error in excess
of that currently implicit in Tier-1 estimates. Credence, though, should
be given to the associated uncertainty

estimates. To facilitate wider adoption of higher-tier methodologies,
our maps could be used to derive new, region-specific default values for
use in Tier-2 frameworks76 or to either

represent or calibrate 2010 baseline conditions in Tier-3 frameworks. In
so doing, inventories and studies alike could more accurately account
for the nuanced global geographies of

biomass C. Usage Notes These maps are intended for global applications
in which continuous spatial estimates of live AGBC and/or BGBC density
are needed that span a broad range of

vegetation types and/or require estimates circa 2010. They are loosely
based upon and share the spatial resolution of the ESA CCI Landcover
2010 map37, which can be used to extract

landcover specific C totals. However, our products notably do not
account for C stored in non-living C pools like litter or coarse woody
debris, nor soil organic matter, though these

both represent large, additional ecosystem C stocks77,78,79. Our maps
are explicitly intended for global scale applications seeking to
consider C in the collective living biomass of

multiple vegetation types. For global scale applications focused
exclusively on the C stocks of a single vegetation type, we strongly
encourage users to instead use the respective

input map or model referenced in Table 1 to avoid potential errors that
may have been introduced by our harmonization procedure. For AGB
applications over smaller extents, users should

further consider whether locally specific products are available. If
such maps are not available and our maps are considered instead,
credence should be given to their pixel-level

uncertainty estimates. As mentioned above, the biomass of shrublands was
only explicitly accounted for in Africa and the Arctic tundra, since
neither broad-scale maps nor models generalizable

to other areas were available in the existing literature. As such, we
caution against the use of our maps outside of these areas when
shrubland biomass is of particular interest or

importance. Moreover, in contrast to the estimates for all other
vegetation types considered, which we upscaled to a 300 m resolution,
cropland C estimates were largely based on relatively

coarse 8 km resolution data that were downscaled using bilinear
resampling to achieve a 300 m spatial resolution. As such, these
estimates may not adequately capture the underlying

finer-scale spatial variation and should be interpreted with that in
mind. Likewise, we reiterate that some BGBC estimates may differ from
locally derived Tier-3 estimates, and attention

should thus be given to our reported pixel-level uncertainty for all
applications. Finally, our maps should not be used in comparison with
the IPCC Tier-1 map of Ruesch and Gibbs (2008)

to detect biomass change between the two study periods due to
significant methodological differences between these products. An
estimated 720 and 811 million people in the world faced

hunger in 2020, according to the United Nations (UN), and nearly one in
three people in the world (2.37 billion) did not have access to adequate
food in 2020. The vulnerabilities and

inadequacies of global food systems are expected to further intensify
over the coming years. The combination of NASA Earth science data with
socioeconomic data provides key information

for sustainable use of available resources. NASA's Socioeconomic Data
and Applications Center (SEDAC) is the home for NASA socioeconomic data
and is a gateway between the social sciences

and the Earth sciences. SEDAC provides numerous datasets and data
collections that may be useful for studies into agriculture and water
management. SEDAC also provides information

about the connections that support efforts to end hunger, achieve food
security and improved nutrition, and promote sustainable agriculture.
Women in the West African country of Senegal

take a break from crushing millet. The United Nations World Food Program
estimates that 46 percent of households in Senegal lack reliable access
to adequate amounts of food. Credit:

Molly Brown Women in the West African country of Senegal take a break
from crushing millet. The United Nations World Food Program estimates
that 46% of households in Senegal lack reliable

access to adequate amounts of food. Credit: Molly Brown. NASA helps
develop tools to address food security and works with decision-makers
and data users to tailor these tools to specific

locations and user needs. These efforts help address issues like water
management for irrigation, crop-type identification and land use,
coastal and lake water quality monitoring,

drought preparedness, and famine early warnings. Much of this work is
carried out and supported fully or in part by the agency's Applied
Sciences Program, which works with individuals

and institutions worldwide to inform decision-making, enhance quality of
life, and strengthen the economy. The Applied Sciences Program co-leads
the international Earth Observations

for Sustainable Development Goals initiative, which advances global
knowledge about effective ways that Earth observations and geospatial
information can support the SDGs. The NASA

datasets and resources listed below, coupled with other data and
resources in this Data Pathfinder, also help measure progress toward
meeting United Nations' Sustainable Development

Goals (SDGs), particularly SDG 2: Zero Hunger. These data can provide a
better overall view for monitoring the food insecurity of vulnerable
populations, tracking agricultural production

related to incomes of small-scale food producers, and monitoring
environmental impacts to soil, water, fertilizer, pesticide pollution,
and changes in biodiversity. More information

is available in the Connection of Sustainable Development Goals to
Agriculture and Water Management section on the main Pathfinder landing
page. Agriculture and Human Dimensions Agriculture

and Food Security theme landing page Global Agricultural Inputs, v1 The
five datasets in this data collection provide global gridded data and
maps on pesticide application, phosphorus

in manure and chemical fertilizers, and nitrogen in manure and chemical
fertilizers Global Pesticide Grids (PEST-CHEMGRIDS), v1.01 (2015, 2020,
2025) Global coverage; 5 arc-min spatial

resolution; GeoTIFF, netCDF-4 Web Map Service Layers Food Supply Effects
of Climate Change on Global Food Production from SRES Emissions and
Socioeconomic Scenarios, v1 (1970 -- 2080)

Global coverage; national resolution; .xlsx Web Map Service Layers Food
Insecurity Hotspots Data Set, v1 (2009 -- 2019) Global coverage;
national resolution; GeoTIFF, Shapefile Web

Map Service Layers Groundswell Spatial Population and Migration
Projections at One-Eighth Degree According to SSPs and RCPs, v1 (2010 --
2050) Allows users to understand how slow-onset

climate change impacts on water availability and crop productivity,
coupled with sea-level rise and storm surge, may affect the future
population distribution and climate-related internal

migration in low to middle income countries Crop Production Twentieth
Century Crop Statistics, v1 (1900 -- 2017) Global coverage (selected
countries); national/sub-national resolution;

annual Global Population Projection Grid Data Groundswell Spatial
Population and Migration Projections at One-Eighth Degree According to
SSPs and RCPs, v1 (2010 -- 2050) Climate Change

Impact Effects of Climate Change on Global Food Production from SRES
Emissions and Socioeconomic Scenarios, v1 (1970 -- 2080) Global
coverage; national resolution; .xlsx Web Map Service

Layers Groundswell Spatial Population and Migration Projections at
One-Eighth Degree According to SSPs and RCPs, v1 (2010 -- 2050)
Environmental Performance 2022 Environmental Performance

Index Global coverage; national resolution; .xlsx, csv 15 static maps
Poverty-related Data Humidity is a measure of the amount of water vapor
present in the air. High humidity impairs

heat exchange efficiency by reducing the rate of moisture evaporation
from the skin and other surfaces. This can create challenges for
agricultural workers, as well as the crops they

grow. The Modern-Era Retrospective analysis for Research and
Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due
to the amount of historical data available, MERRA-2

data can be used to look for trends and patterns as well as anomalies.
There are several options available: 1-hourly, 3-hourly, 6-hourly,
daily, and monthly. These options provide

information on precipitation. The NASA Earth Exchange Global Daily
Downscaled Projections (NEX-GDDP) dataset is comprised of
high-resolution, bias-corrected global downscaled climate

projections derived from the General Circulation Model (GCM) runs
conducted under the Coupled Model Intercomparison Project Phase 6
(CMIP6) and across all four "Tier 1" greenhouse

gas emissions scenarios known as Shared Socioeconomic Pathways (SSPs).
This dataset provides a set of global, high resolution, bias-corrected
climate change projections that can be

used to evaluate climate change impacts on processes that are sensitive
to finer-scale climate gradients and the effects of local topography on
climate conditions. Uses include: air

temperature, precipitation volume, humidity, stellar radiation, and
atmospheric wind speed. The atmosphere is a mixture of gases that
surrounds the Earth. It helps make life possible

by providing us with air to breathe, shielding us from harmful
ultraviolet (UV) radiation coming from the Sun, trapping heat to warm
the planet, and preventing extreme temperature

differences between day and night. Without the atmosphere, temperatures
would be well below freezing everywhere on Earth's surface. Instead, the
heat absorbed and trapped by our atmosphere

keeps our planet's average surface temperature at a balmy 15°C (59°F).
Some of the atmosphere's gases, like carbon dioxide, are particularly
good at absorbing and trapping radiation.

Changes in the amounts of these gases directly affect our climate. Gases
in Earth's Atmosphere Each of the planets in our solar system has an
atmosphere, but none of them have the

same ratio of gases or layered structure as Earth's atmosphere. Nitrogen
and oxygen are by far the most common gases in our atmosphere. Dry air
is composed of about 78% nitrogen (N2)

and about 21% oxygen (O2). The remaining less than 1% of the atmosphere
is a mixture of gases, including argon (Ar) and carbon dioxide (CO2).
The atmosphere also contains varying amounts

of water vapor, on average about 1%. There are also many, tiny, solid or
liquid particles, called aerosols, in the atmosphere. Aerosols can be
made of dust, spores and pollen, salt

from sea spray, volcanic ash, smoke, and pollutants introduced through
human activity. Earth's Atmosphere Has Layers The atmosphere becomes
thinner (less dense and lower in air pressure)

the further it extends from the Earth's surface. It gradually gives way
to the vacuum of space. There is no precise top of the atmosphere, but
the area between 100-120 km (62-75 miles)

above the Earth's surface is often considered the boundary between the
atmosphere and space because the air is so thin here. However, there are
measurable traces of atmospheric gases

beyond this boundary, detectable for hundreds of kilometers/miles from
Earth's surface. There are several unique layers in Earth's atmosphere.
Each has characteristic temperatures,

pressures, and phenomena. We live in the troposphere, the layer closest
to Earth's surface, where most clouds are found and almost all weather
occurs. Some jet aircraft fly in the

next layer, the stratosphere, which contains the jet streams and a
region called the ozone layer. The next layer, the mesosphere, is the
coldest because the there are almost no air

molecules there to absorb heat energy. There are so few molecules for
light to refract off of that the sky also changes from blue to black in
this layer. And farthest from the surface

we have the thermosphere, which absorbs much of the harmful radiation
that reaches Earth from the Sun, causing this layer to reach extremely
high temperatures. Beyond the thermosphere

is the exosphere, which represents the transition from Earth's
atmosphere to space. Planetary Atmospheres Earth is not the only world
with an atmosphere. Each of the planets - and

even a few moons - in our solar system have an atmosphere. Some planets
have active atmospheres with clouds, wind, rain and powerful storms.
Scientists use light spectroscopy to observe

the atmospheres of planets and moons in other solar systems . Each of
the planets in our solar system has a uniquely structured atmosphere.
The atmosphere of Mercury is extremely thin

and is not very different from the vacuum of space. The gas giant
planets in our solar system - Jupiter, Saturn, Uranus and Neptune - each
have a thick, deep atmosphere. The smaller,

rocky planets - Earth, Venus and Mars - each have thinner atmospheres,
hovering above their solid surfaces. The moons in our solar system
typically have thin atmospheres, with the

exception of Saturn's moon, Titan. Air pressure at the surface of Titan
is higher than on Earth! Of the five officially recognized dwarf
planets, Pluto has a thin atmosphere that expands

and collapses seasonally, and Ceres has an extremely thin and transient
atmosphere made of water vapor. But only Earth's atmosphere has the
layered structure that traps enough of the

Sun's energy for warmth while also blocking much of the harmful
radiation from the Sun. This important balance is necessary to maintain
life on Earth. Forests are one of the world's

largest banks of carbon-rich biomass. This is why when researchers
mapped biomass in the past, they typically focused on the world's
forests. But this approach leaves out considerable

amounts of biomass in grasslands, shrublands, croplands, and other
biomes. New maps, published at NASA's Oak Ridge National Laboratory
Distributed Active Archive Center (ORNL DAAC)

and described in Nature Scientific Data, combine remotely sensed biomass
data for different land cover types into harmonized global maps of above
and belowground biomass for the year

2010. People often conflate forest biomass with total biomass," said
      Seth Spawn, lead author of the research and doctoral candidate at
      the University of Wisconsin, Madison. "Researchers

have spent a lot of time developing nice remotely sensed maps of
aboveground forest biomass, but they intentionally omit other land
covers and the carbon stored below ground in plant

roots. We haven't had the whole picture." Spawn and his team combined
maps of forest biomass with other land cover specific biomass maps that
use remotely sensed data. They allocated

fractional contributions to a given grid cell using data on land cover,
percent tree cover, and the presence of secondary vegetation. These maps
show a sizable stock of biomass outside

of forested areas, especially in the trees located in savannas and farm
fields. "There's more carbon on croplands than I would have expected,"
said Spawn. Trees on orchards and farms

practicing agroforestry have a carbon stock that is overlooked in
previous biomass maps. Globally, trees on croplands stored about 28
metric gigatons of carbon in 2010, which is 7

percent of the total stock of carbon in plants, according to these new
maps. The team produced maps of uncertainty with the data they used and
published them along with the dataset.

Published in March, the dataset is already being used for a number of
applications. Researchers are using the dataset in integrated assessment
models that incorporate economics and

the Earth system. It is also being used to model carbon emissions from
past and potential land use changes and the carbon impacts of bioenergy
transitions. Water is a key component

of the overall Earth system, cycling through each component, moving
within the atmosphere, the ocean, the cryosphere (including snow cover
and snowpack), surface water of rivers and

lakes, and subsurface water. Water availability is critical for human
consumption, agriculture and food security, industry, and energy
development. Assessing water availability, including

the amount and type of precipitation is critical to monitoring
agricultural practices and water resource availability and for providing
interventions when necessary. According to the

U.N., water use has been growing globally at twice the rate as the
global population is increasing. More and more areas are reaching the
limit at which water services can be sustainably

delivered, especially in arid regions. Groundwater, a major water
resource for maintaining cropland productivity, is declining through the
extensive use of water for agricultural irrigation,

where aquifer recharge cannot keep up with groundwater extraction.
Unfortunately, changes in terrestrial water storage, especially with
regard to groundwater, are poorly known and

sparsely sampled. Complicating matters further, global freshwater is not
only unevenly distributed, but sources of freshwater such as lakes and
rivers often cross geopolitical boundaries.

Integrating satellite data with land-based and other measurements,
geospatial data, and hydrologic models help to better understand
controls on global water resources and how changing

water resources impact social-environmental systems across geopolitical
boundaries. Earth Observation Data by Sensor According to the U.N.,
water use has been growing globally at twice

the rate as the global population is increasing. More and more areas are
reaching the limit at which water services can be sustainably delivered,
especially in arid regions. Groundwater,

a major water resource for maintaining cropland productivity, is
declining through the extensive use of water for agricultural
irrigation, where aquifer recharge cannot keep up with

groundwater extraction. Unfortunately, changes in terrestrial water
storage, especially with regard to groundwater, are poorly known and
sparsely sampled. Complicating matters further,

global freshwater is not only unevenly distributed, but sources of
freshwater such as lakes and rivers often cross geopolitical boundaries.
Integrating satellite data with land-based

and other measurements, geospatial data, and hydrologic models help to
better understand controls on global water resources and how changing
water resources impact social-environmental

systems across geopolitical boundaries. Earth Observation Data by Sensor
GRACE, GRACE-FO Instruments aboard the joint NASA/German Space Agency
Gravity Recovery And Climate Experiment

(GRACE, operational 2002 to 2017) and GRACE Follow-On (GRACE-FO,
launched in 2018) satellites obtain measurements about changes in
Earth's gravity. Since water has mass, changes in

groundwater storage can be detected as changes in gravity. GRACE and
GRACE-FO measurements help assess water storage changes in monthly,
total surface, and groundwater depth. These

data are available from 2002 to present; the data track total water
storage time-variations and anomalies (changes from the time-mean) at a
resolution of approximately 90,000 km2 and

larger. These measurements are unimpeded by clouds and track the entire
land water column from the surface down to deep aquifers. GRACE and
GRACE-FO data are uniquely valuable for

regional studies to determine general trends in land water storage as
well as for assessing basin-scale water budgets (e.g., the balance
between precipitation, evapotranspiration,

and runoff). GRACE and GRACE-FO Mascon Ocean, Ice, and Hydrology
Equivalent Water Height dataset provides gridded monthly global water
storage/height anomalies relative to a time-mean.

The data are processed at NASA's Jet Propulsion Laboratory (JPL) using
the mascon approach. Mass Concentration blocks (mascons) are a form of
gravity field basis functions to which

GRACE observations are optimally fit. For more information on this
approach, see the JPL Monthly Mass Grids webpage. Data are represented
as Water Equivalent Thickness (WET), representing

the total terrestrial water storage anomalies from soil moisture, snow,
surface water (including rivers, lakes, and reservoirs), as well as
groundwater and aquifers. Scientists at

NASA's Goddard Space Flight Center use GRACE-FO data to generate weekly
groundwater and soil moisture drought indicators. The drought indicators
describe current wet or dry conditions,

expressed as a percentile showing the probability of occurrence for a
specific location and time of year, with lower values (orange/red)
indicating drier than normal conditions and

higher values (blues) indicating wetter than normal conditions. The
drought model is also used to make forecasts of expected drought
conditions one, two, and three months into the

future. NASA, in collaboration with other agencies, has developed models
of groundwater that incorporate satellite information with ground-based
data (when ground-based data are available).

These models are part of the Land Data Assimilation System (LDAS), which
includes a global collection (GLDAS) and a North American collection
(NLDAS). NASA's Goddard Earth Sciences

Data and Information Services Center (GES DISC) optimally reorganized
some large hydrological datasets as time series (also known as data
rods) for a set of water cycle-related variables

from the NLDAS and GLDAS, the Land Parameter Parameter Model (LPRM),
TRMM, and GRACE data assimilation. These are available at GES DISC
Hydrology Data Rods. The Modern-Era Retrospective

analysis for Research and Applications, Version 2 (MERRA-2) provides
data beginning in 1980. Due to the amount of historical data available,
MERRA-2 data can be used to look for trends

and patterns, as well as anomalies. There are several options available:
hourly and monthly from 1980. Remote sensing is the acquiring of
information from a distance. NASA observes

Earth and other planetary bodies via remote sensors on satellites and
aircraft that detect and record reflected or emitted energy. Remote
sensors, which provide a global perspective

and a wealth of data about Earth systems, enable data-informed decision
making based on the current and future state of our planet. Satellites
can be placed in several types of orbits

around Earth. The three common classes of orbits are low-Earth orbit
(approximately 160 to 2,000 km above Earth), medium-Earth orbit
(approximately 2,000 to 35,500 km above Earth),

and high-Earth orbit (above 35,500 km above Earth). Satellites orbiting
at 35,786 km are at an altitude at which their orbital speed matches the
planet's rotation, and are in what

is called geosynchronous orbit (GSO). In addition, a satellite in GSO
directly over the equator will have a geostationary orbit. A
geostationary orbit enables a satellite to maintain

its position directly over the same place on Earth's surface. Aqua
satellite orbit illustrating polar orbital track. NASA's Aqua satellite
completes one orbit every 99 minutes and

passes within 10 degrees of each pole. This enables the Moderate
Resolution Imaging Spectroradiometer (MODIS) aboard Aqua to acquire full
global imagery every 1-2 days. Credit: NASA

Aqua. Low-Earth orbit is a commonly used orbit since satellites can
follow several orbital tracks around the planet. Polar-orbiting
satellites, for example, are inclined nearly 90

degrees to the equatorial plane and travel from pole to pole as Earth
rotates. This enables sensors aboard the satellite to acquire data for
the entire globe rapidly, including the

polar regions. Many polar-orbiting satellites are considered
Sun-synchronous, meaning that the satellite passes over the same
location at the same solar time each cycle. One example

of a Sun-synchronous, polar-orbiting satellite is NASA's Aqua satellite,
which orbits approximately 705 km above Earth's surface. Non-polar
low-Earth orbit satellites, on the other

hand, do not provide global coverage but instead cover only a partial
range of latitudes. The joint NASA/Japan Aerospace Exploration Agency
Global Precipitation Measurement (GPM) Core

Observatory is an example of a non-Sun-synchronous low-Earth orbit
satellite. Its orbital track acquires data between 65 degrees north and
south latitude from 407 km above the planet.

A medium-Earth orbit satellite takes approximately 12 hours to complete
an orbit. In 24-hours, the satellite crosses over the same two spots on
the equator every day. This orbit is

consistent and highly predictable. As a result, this is an orbit used by
many telecommunications and GPS satellites. One example of a
medium-Earth orbit satellite constellation is

the European Space Agency's Galileo global navigation satellite system
(GNSS), which orbits 23,222 km above Earth. While both geosynchronous
and geostationary satellites orbit at 35,786

km above Earth, geosynchronous satellites have orbits that can be tilted
above or below the equator. Geostationary satellites, on the other hand,
orbit Earth on the same plane as the

equator. These satellites capture identical views of Earth with each
observation and provide almost continuous coverage of one area. The
joint NASA/NOAA Geostationary Operational Environmental

Satellite (GOES) series of weather satellites are in geostationary
orbits above the equator. Observing with the Electromagnetic Spectrum
Electromagnetic energy, produced by the vibration

of charged particles, travels in the form of waves through the
atmosphere and the vacuum of space. These waves have different
wavelengths (the distance from wave crest to wave crest)

and frequencies; a shorter wavelength means a higher frequency. Some,
like radio, microwave, and infrared waves, have a longer wavelength,
while others, such as ultraviolet, x-rays,

and gamma rays, have a much shorter wavelength. Visible light sits in
the middle of that range of long to shortwave radiation. This small
portion of energy is all that the human eye

is able to detect. Instrumentation is needed to detect all other forms
of electromagnetic energy. NASA instrumentation utilizes the full range
of the spectrum to explore and understand

processes occurring here on Earth and on other planetary bodies. Some
waves are absorbed or reflected by atmospheric components, like water
vapor and carbon dioxide, while some wavelengths

allow for unimpeded movement through the atmosphere; visible light has
wavelengths that can be transmitted through the atmosphere. Microwave
energy has wavelengths that can pass through

clouds, an attribute utilized by many weather and communication
satellites. The primary source of the energy observed by satellites, is
the Sun. The amount of the Sun's energy reflected

depends on the roughness of the surface and its albedo, which is how
well a surface reflects light instead of absorbing it. Snow, for
example, has a very high albedo and reflects up

to 90% of incoming solar radiation. The ocean, on the other hand,
reflects only about 6% of incoming solar radiation and absorbs the rest.
Often, when energy is absorbed, it is re-emitted,

usually at longer wavelengths. For example, the energy absorbed by the
ocean gets re-emitted as infrared radiation. All things on Earth
reflect, absorb, or transmit energy, the amount

of which varies by wavelength. Just as your fingerprint is unique to
you, everything on Earth has a unique spectral fingerprint. Researchers
can use this information to identify different

Earth features as well as different rock and mineral types. The number
of spectral bands detected by a given instrument, its spectral
resolution, determines how much differentiation

a researcher can identify between materials. Drought, vegetation health,
and soil moisture all can be tracked remotely. This Data Pathfinder
provides links to NASA Earth observations,

tools, and other resources applicable to agricultural production and
water management. The planet NASA studies the most is Earth. NASA's
end-to-end Earth observations enable agricultural

producers to make informed decisions about global market conditions,
water management, in-season crop conditions, severe weather, and
sustainability. This Data Pathfinder will help

guide you through the process of selecting and using datasets applicable
to agriculture and water management, and provides links to specific data
sources. If you are new to remote

sensing, the What is Remote Sensing? Backgrounder provides a
comprehensive overview. In addition, NASA's Applied Remote Sensing
Training Program (ARSET) provides numerous training

What's big, covered in water, yet 100 times drier than the Sahara
Desert? It's not a riddle, it's the Moon! For centuries, astronomers
debated whether water exists on Earth's closest neighbor. In 2020, data
from NASA's SOFIA mission confirmed water exists in the sunlit area of
the lunar surface as molecules of H2O embedded within, or perhaps
sticking to the surface of, grains of lunar dust. Here is a brief
history of the discoveries leading up to the confirmation of water on
the Moon.

When early astronomers looked up at the Moon, they were struck by the
large, dark spots on its surface. In 1645, Dutch astronomer Michael van
Langren published the first-known map of the Moon referring to the dark
spots as "maria" -- the Latin word for "seas" -- and putting into
writing the widely-held view that the marks were oceans on the lunar
surface. Similar maps from Johannes Hevelius (1647), Giovanni Riccioli
and Francesco Grimaldi (1651) were published over the next few years. We
now know these spots to be plains of basalt created by early volcanic
eruptions, but the nomenclature of 'maria' (plural) or 'mare' (singular)
remains.

American astronomer William Pickering made measurements in the late
1800s that led him to conclude the Moon essentially has no atmosphere.
With no clouds and no atmosphere, scientists generally agreed that any
water on the lunar surface would evaporate immediately. Pickering's
measurements led to a widespread view that the Moon was devoid of water.

As scientists made headway in understanding the behavior of substances
that are prone to vaporize at relatively low temperatures -- called
volatiles -- theoretical physicist Kenneth Watson published a paper in
1961 describing how a substance like water could exist on the Moon.
Watson's paper first popularized the idea that water ice could stick to
the bottom of craters on the Moon that never receive light from the Sun,
while sunlit areas on the Moon would be so hot that water would
evaporate near-instantly. These lightless areas of the Moon are called
"permanently shadowed regions."

The Apollo era brought humans to the lunar surface for the very first
time, giving researchers the opportunity to directly look for signs of
water on the Moon. When tested, soil samples brought back by Apollo
astronauts revealed no sign of water. Scientists concluded that the
lunar surface must be completely dry, and the prospect of water wasn't
seriously considered again for decades.

NASA's Clementine mission launched in 1994 to orbit the Moon for two
months and collect information about its minerals. Clementine data
suggested there was ice in a permanently shadowed region of the Moon.
The Lunar Prospector Mission focused on permanently shadowed craters to
look deeper into the discovery and in 1998 found that the largest
concentrations of hydrogen exist in the areas of the lunar surface that
are never exposed to sunlight. The results indicated water ice at the
lunar poles. However, the images were low resolution so no strong
conclusions could be made.

Capitalizing on major advances in technology since the Apollo era,
researchers from Brown University revisited the Apollo samples. They
found hydrogen inside tiny beads of volcanic glass. Since no volcanoes
are erupting on the Moon today, the discovery presented evidence that
water had existed in the Moon when the volcanoes erupted in the Moon's
ancient past. Additionally, the preserved hydrogen provided clues to the
origins of lunar water: if it emerged from erupting volcanoes, it must
have come from within the Moon. The discovery suggested that water was a
part of the Moon since its early existence -- and perhaps since it first
formed.

A suite of spacecraft enabled exciting discoveries in 2009. None were
designed to look for water on the Moon, yet the Indian Space Research
Organization's Chandrayaan-1 and NASA's Cassini and Deep Impact missions
detected signs of hydrated minerals in the form of oxygen and hydrogen
molecules in sunlit areas of the Moon. Researchers couldn't determine
whether they were seeing hydration by hydroxyl (OH) or water (H2O). They
also debated whether the amount of hydration depended on the time of
day.

The Lunar Crater Observation and Sensing Satellite (LCROSS) spacecraft
and Lunar Reconnaissance Orbiter (LRO) launched together in 2009. Later
that year, LCROSS intentionally discharged a projectile into a crater
believed to contain water ice, and flew through the debris from the
projectile's impact. Four minutes later, LCROSS itself intentionally
impacted the Moon while LRO observed. The combined observations showed
grains of water ice in the ejected material. The LRO and LCROSS findings
added to a growing body of evidence that water exists on the Moon in the
form of ice within permanently shadowed regions. LRO continues to orbit
the Moon and provide data used to characterize and map lunar resources,
including hydrogen.

Data from Moon Mineralogy Mapper (M3), carried by ISRO's Chandrayaan-1,
provided scientists with the first high-resolution map of the minerals
that make up the lunar surface. The NASA instrument flew aboard India's
Chandrayaan-1 mission in 2009. An analysis of the full set of data from
M3, announced in 2018, revealed multiple confirmed locations of water
ice in permanently shadowed regions of the Moon.

In 2020, NASA announced the discovery of water on the sunlit surface of
the Moon. Data from the Strategic Observatory for Infrared Astronomy
(SOFIA), revealed that in Clavius crater, water exists in concentrations
roughly equivalent to a 12-ounce bottle of water within a cubic meter of
soil across the lunar surface. The discovery showed that water could be
distributed across the lunar surface, even on sunlit portions, and not
confined to cold, dark areas.

In 2023, a new map of water distribution on the Moon provided hints
about how water may be moving across the Moon's surface. The map, made
using SOFIA data, extends to the Moon's South Pole -- the intended
region of study for NASA's Artemis missions, including the water-hunting
rover, VIPER.

Researchers have confirmed that water exists both in the sunlit and
shadowed surfaces of the Moon, yet many questions remain. Lunar
scientists continue to investigate the origins of water and its
behavior. There is evidence that the water on the Moon comes from
ancient and current comet impacts, icy micrometeorites colliding on the
lunar surface, and lunar dust interactions with the solar wind. However,
more research is needed to understand the full history, present, and
future of water on the Moon. Writer: Allison Gasparini and Molly
Wasser`\nScience `{=tex}Advisors: Casey Honniball, Tim Livengood, NASA's
Goddard Space Flight Center In 2019, scientists discovered that water is
being released from the Moon during meteor showers. Water on the Moon
could come from a surprising source, our Sun. In 2020, NASA scientists
confirmed the presence of H2O on the Moon.

Viewed from space, one of the most striking features of our home planet
is the water, in both liquid and frozen forms, that covers approximately
75% of the Earth's surface. Geologic evidence suggests that large
amounts of water have likely flowed on Earth for the past 3.8 billion
years---most of its existence. Believed to have initially arrived on the
surface through the emissions of ancient volcanoes, water is a vital
substance that sets the Earth apart from the rest of the planets in our
solar system. In particular, water appears to be a necessary ingredient
for the development and nourishment of life.

Water is practically everywhere on Earth. Moreover, it is the only known
substance that can naturally exist as a gas, a liquid, and solid within
the relatively small range of air temperatures and pressures found at
the Earth's surface. In all, the Earth's water content is about 1.39
billion cubic kilometers (331 million cubic miles), with the bulk of it,
about 96.5%, being in the global oceans. As for the rest, approximately
1.7% is stored in the polar icecaps, glaciers, and permanent snow, and
another 1.7% is stored in groundwater, lakes, rivers, streams, and soil.
Only a thousandth of 1% of the water on Earth exists as water vapor in
the atmosphere.

Despite its small amount, this water vapor has a huge influence on the
planet. Water vapor is a powerful greenhouse gas, and it is a major
driver of the Earth's weather and climate as it travels around the
globe, transporting latent heat with it. Latent heat is heat obtained by
water molecules as they transition from liquid or solid to vapor; the
heat is released when the molecules condense from vapor back to liquid
or solid form, creating cloud droplets and various forms of
precipitation. For human needs, the amount of freshwater on Earth---for
drinking and agriculture---is particularly important. Freshwater exists
in lakes, rivers, groundwater, and frozen as snow and ice. Estimates of
groundwater are particularly difficult to make, and they vary widely.
(The value in the above table is near the high end of the range.)
Groundwater may constitute anywhere from approximately 22 to 30% of
fresh water, with ice (including ice caps, glaciers, permanent snow,
ground ice, and permafrost) accounting for most of the remaining 78 to
70%.

The water, or hydrologic, cycle describes the pilgrimage of water as
water molecules make their way from the Earth's surface to the
atmosphere and back again, in some cases to below the surface. This
gigantic system, powered by energy from the Sun, is a continuous
exchange of moisture between the oceans, the atmosphere, and the land.

Studies have revealed that evaporation---the process by which water
changes from a liquid to a gas---from oceans, seas, and other bodies of
water (lakes, rivers, streams) provides nearly 90% of the moisture in
our atmosphere. Most of the remaining 10% found in the atmosphere is
released by plants through transpiration. Plants take in water through
their roots, then release it through small pores on the underside of
their leaves. In addition, a very small portion of water vapor enters
the atmosphere through sublimation, the process by which water changes
directly from a solid (ice or snow) to a gas. The gradual shrinking of
snow banks in cases when the temperature remains below freezing results
from sublimation.

Together, evaporation, transpiration, and sublimation, plus volcanic
emissions, account for almost all the water vapor in the atmosphere that
isn't inserted through human activities. While evaporation from the
oceans is the primary vehicle for driving the surface-to-atmosphere
portion of the hydrologic cycle, transpiration is also significant. For
example, a cornfield 1 acre in size can transpire as much as 4,000
gallons of water every day.

After the water enters the lower atmosphere, rising air currents carry
it upward, often high into the atmosphere, where the air is cooler. In
the cool air, water vapor is more likely to condense from a gas to a
liquid to form cloud droplets. Cloud droplets can grow and produce
precipitation (including rain, snow, sleet, freezing rain, and hail),
which is the primary mechanism for transporting water from the
atmosphere back to the Earth's surface.

When precipitation falls over the land surface, it follows various
routes in its subsequent paths. Some of it evaporates, returning to the
atmosphere; some seeps into the ground as soil moisture or groundwater;
and some runs off into rivers and streams. Almost all of the water
eventually flows into the oceans or other bodies of water, where the
cycle continues. At different stages of the cycle, some of the water is
intercepted by humans or other life forms for drinking, washing,
irrigating, and a large variety of other uses.

Groundwater is found in two broadly defined layers of the soil, the
"zone of aeration," where gaps in the soil are filled with both air and
water, and, further down, the "zone of saturation," where the gaps are
completely filled with water. The boundary between these two zones is
known as the water table, which rises or falls as the amount of
groundwater changes.

The amount of water in the atmosphere at any moment in time is only
12,900 cubic kilometers, a minute fraction of Earth's total water
supply: if it were to completely rain out, atmospheric moisture would
cover the Earth's surface to a depth of only 2.5 centimeters. However,
far more water---in fact, some 495,000 cubic kilometers of it---are
cycled through the atmosphere every year. It is as if the entire amount
of water in the air were removed and replenished nearly 40 times a year.

Water continually evaporates, condenses, and precipitates, and on a
global basis, evaporation approximately equals precipitation. Because of
this equality, the total amount of water vapor in the atmosphere remains
approximately the same over time. However, over the continents,
precipitation routinely exceeds evaporation, and conversely, over the
oceans, evaporation exceeds precipitation.

In the case of the oceans, the continual excess of evaporation versus
precipitation would eventually leave the oceans empty if they were not
being replenished by additional means. Not only are they being
replenished, largely through runoff from the land areas, but over the
past 100 years, they have been over-replenished: sea level around the
globe has risen approximately 17 centimeters over the course of the
twentieth century.

Sea level has risen both because of warming of the oceans, causing water
to expand and increase in volume, and because more water has been
entering the ocean than the amount leaving it through evaporation or
other means. A primary cause for increased mass of water entering the
ocean is the calving or melting of land ice (ice sheets and glaciers).
Sea ice is already in the ocean, so increases or decreases in the annual
amount of sea ice do not significantly affect sea level.

Throughout the hydrologic cycle, there are many paths that a water
molecule might follow. Water at the bottom of Lake Superior may
eventually rise into the atmosphere and fall as rain in Massachusetts.
Runoff from the Massachusetts rain may drain into the Atlantic Ocean and
circulate northeastward toward Iceland, destined to become part of a
floe of sea ice, or, after evaporation to the atmosphere and
precipitation as snow, part of a glacier.

Water molecules can take an immense variety of routes and branching
trails that lead them again and again through the three phases of ice,
liquid water, and water vapor. For instance, the water molecules that
once fell 100 years ago as rain on your great- grandparents' farmhouse
in Iowa might now be falling as snow on your driveway in California.

Among the most serious Earth science and environmental policy issues
confronting society are the potential changes in the Earth's water cycle
due to climate change. The science community now generally agrees that
the Earth's climate is undergoing changes in response to natural
variability, including solar variability, and increasing concentrations
of greenhouse gases and aerosols. Furthermore, agreement is widespread
that these changes may profoundly affect atmospheric water vapor
concentrations, clouds, precipitation patterns, and runoff and stream
flow patterns. For example, as the lower atmosphere becomes warmer,
evaporation rates will increase, resulting in an increase in the amount
of moisture circulating throughout the troposphere (lower atmosphere).
An observed consequence of higher water vapor concentrations is the
increased frequency of intense precipitation events, mainly over land
areas. Furthermore, because of warmer temperatures, more precipitation
is falling as rain rather than snow.

In parts of the Northern Hemisphere, an earlier arrival of spring-like
conditions is leading to earlier peaks in snowmelt and resulting river
flows. As a consequence, seasons with the highest water demand,
typically summer and fall, are being impacted by a reduced availability
of fresh water.

Warmer temperatures have led to increased drying of the land surface in
some areas, with the effect of an increased incidence and severity of
drought. The Palmer Drought Severity Index, which is a measure of soil
moisture using precipitation measurements and rough estimates of changes
in evaporation, has shown that from 1900 to 2002, the Sahel region of
Africa has been experiencing harsher drought conditions. This same index
also indicates an opposite trend in southern South America and the south
central United States.

While the brief scenarios described above represent a small portion of
the observed changes in the water cycle, it should be noted that many
uncertainties remain in the prediction of future climate. These
uncertainties derive from the sheer complexity of the climate system,
insufficient and incomplete data sets, and inconsistent results given by
current climate models. However, state of the art (but still incomplete
and imperfect) climate models do consistently predict that precipitation
will become more variable, with increased risks of drought and floods at
different times and places.

Orbiting satellites are now collecting data relevant to all aspects of
the hydrologic cycle, including evaporation, transpiration,
condensation, precipitation, and runoff. NASA even has one satellite,
Aqua, named specifically for the information it is collecting about the
many components of the water cycle.

Aqua launched on May 4, 2002, with six Earth-observing instruments: the
Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding
Unit (AMSU), the Humidity Sounder for Brazil (HSB), the Advanced
Microwave Scanning Radiometer for the Earth Observing System (AMSR-E),
the Moderate Resolution Imaging Spectroradiometer (MODIS), and Clouds
and the Earth's Radiant Energy System (CERES).

Since water vapor is the Earth's primary greenhouse gas, and it
contributes significantly to uncertainties in projections of future
global warming, it is critical to understand how it varies in the Earth
system. In the first years of the Aqua mission, AIRS, AMSU, and HSB
provided space-based measurements of atmospheric temperature and water
vapor that were more accurate than any obtained before; the sensors also
made measurements from more altitudes than any previous sensor. The HSB
is no longer operational, but the AIRS/AMSU system continues to provide
high-quality atmospheric temperature and water vapor measurements.

More recent studies using AIRS data have demonstrated that most of the
warming caused by carbon dioxide does not come directly from carbon
dioxide, but rather from increased water vapor and other factors that
amplify the initial warming. Other studies have shown improved
estimation of the landfall of a hurricane in the Bay of Bengal by
incorporating AIRS temperature measurements, and improved understanding
of large-scale atmospheric patterns such as the Madden-Julian
Oscillation.

In addition to their importance to our weather, clouds play a major role
in regulating Earth's climate system. MODIS, CERES, and AIRS all collect
data relevant to the study of clouds. The cloud data include the height
and area of clouds, the liquid water they contain, and the sizes of
cloud droplets and ice particles. The size of cloud particles affects
how they reflect and absorb incoming sunlight, and the reflectivity
(albedo) of clouds plays a major role in Earth's energy balance.

One of the many variables AMSR-E monitors is global precipitation. The
sensor measures microwave energy, some of which passes through clouds,
and so the sensor can detect the rainfall even under the clouds.

Water in the atmosphere is hardly the only focus of the Aqua mission.
Among much else, AMSR-E and MODIS are being used to study sea ice. Sea
ice is important to the Earth system not just as an important element in
the habitat of polar bears, penguins, and some species of seals, but
also because it can insulate the underlying liquid water against heat
loss to the often frigid overlying polar atmosphere and because it
reflects sunlight that would otherwise be available to warm the ocean.

When it comes to sea ice, AMSR-E and MODIS provide complementary
information. AMSR-E doesn't record as much detail about ice features as
MODIS does, but it can distinguish ice versus open water even when it is
cloudy. The AMSR-E measurements continue, with improved resolution and
accuracy, a satellite record of changes in the extent of polar ice that
extends back to the 1970s.

AMSR-E and MODIS also provide monitoring of snow coverage over land,
another key indicator of climate change. As with sea ice, AMSR-E allows
routine monitoring of the snow, irrespective of cloud cover, but with
less spatial detail, while MODIS sees greater spatial detail, but only
under cloud-free conditions.

As for liquid water on land, AMSR-E provides information about soil
moisture, which is crucial for vegetation including agricultural crops.
AMSR-E's monitoring of soil moisture globally permits, for example, the
early identification of signs of drought. Aqua is the most comprehensive
of NASA's water cycle missions, but it isn't alone. In fact, the Terra
satellite also has MODIS and CERES instruments onboard, and several
other spacecraft have made or are making unique water-cycle
measurements.

The Ice, Cloud, and Land Elevation Satellite (ICESat) was launched in
January 2003, and it collected data on the topography of the Earth's ice
sheets, clouds, vegetation, and the thickness of sea ice off and on
until October 2009. A new ICESat mission, ICESat-2, is now under
development and is scheduled to launch in 2015.

The Gravity Recovery and Climate Experiment (GRACE) is a unique mission
that consists of two spacecraft orbiting one behind the other; changes
in the distance between the two provide information about the gravity
field on the Earth below. Because gravity depends on mass, some of the
changes in gravity over time signal a shift in water from one place on
Earth to another. Through measurements of changing gravity fields, GRACE
scientists are able to derive information about changes in the mass of
ice sheets and glaciers and even changes in groundwater around the
world.

CloudSat is advancing scientists' understanding of cloud abundance,
distribution, structure, and radiative properties (how they absorb and
emit energy, including thermal infrared energy escaping from Earth's
surface). Since 2006, CloudSat has flown the first satellite-based,
millimeter-wavelength cloud radar---an instrument that is 1000 times
more sensitive than existing weather radars on the ground. Unlike
ground-based weather radars that use centimeter wavelengths to detect
raindrop-sized particles, CloudSat's radar allows the detection of the
much smaller particles of liquid water and ice in the large cloud masses
that contribute significantly to our weather.

The joint NASA and French Cloud-Aerosol Lidar and Infrared Pathfinder
Satellite Observations (CALIPSO) is providing new insight into the role
that clouds and atmospheric aerosols (particles like dust and pollution)
play in regulating Earth's weather, climate, and air quality. CALIPSO
combines an active laser instrument with passive infrared and visible
imagers to probe the vertical structure and properties of thin clouds
and aerosols over the globe.

July through October fall within the dry season in the western and
northern Amazon rainforest, but a particularly acute lack of rain during
this period in 2023 has pushed the region into a severe drought. The OLI
(Operational Land Imager) instrument on Landsat 8 captured this image
(right) of the parched Rio Negro in the Brazilian province of Amazonas
near the city of Manaus on October 3, 2023. On that date, the level of
the river, the largest tributary of the Amazon River, had dropped to
15.14 meters (50.52 feet), according to data collected by the Port of
Manaus.

For comparison, the image on the left shows the same area on October 8,
2022, when the water level was 19.59 meters, a more typical level for
October. Rio Negro water levels continued to drop in the days after the
image was collected, reaching a record low of 13.49 meters on October
17, 2023. Some areas in the Amazon River's watershed have received less
rain between July and September than any year since 1980, Reuters
reported. The drought has been particularly severe in the Rio Negro
watershed in northern Amazonas, as well as parts of southern Venezuela
and southern Colombia. "Overall, this is a pretty unusual and extreme
situation," said René Garreaud, an atmospheric scientist at the
University of Chile.

"The primary culprit exacerbating the drought appears to be El Niño."

This cyclical warming of surface waters in the central-eastern Pacific
functions somewhat like a boulder in the middle of a stream, disrupting
atmospheric circulation patterns in ways that lead to wetter conditions
over the equatorial Pacific and drier conditions over the Amazon Basin.
According to news outlets, the low river water levels on the Rio Negro
and other nearby rivers have disrupted drinking water supplies in
hundreds of communities, slowed commercial navigation, and led to fish
and dolphin die-offs.

Manaus, the capital and largest city of the Brazilian state of Amazonas,
is the primary transportation hub for the upper Amazon, serving as an
important transit point for soap, beef, and animal hides. Other
industries with a presence in the city of two million people include
chemical, ship, and electrical equipment manufacturing.

After rapidly growing in volume just a few years earlier, northwest
Iran's Lake Urmia nearly dried out in autumn 2023. The largest lake in
the Middle East and one of the largest hypersaline lakes on Earth at its
greatest extent, Lake Urmia has for the most part transformed into a
vast, dry salt flat.

It stands in contrast to the image from three years earlier (left),
acquired by the OLI on Landsat 8 on September 8, 2020, when water filled
most of the basin and salt deposits were only visible around the
perimeter of the lake.

The replenishment followed a period of above-average precipitation that
sent a surge of freshwater into the basin, expanding its watery
footprint. Drier conditions have since brought levels back down. The
longer-term trend for Urmia has been one toward drying. In 1995, Lake
Urmia reached a high-water mark; then in the ensuing two decades, the
lake level dropped more than 7 meters (23 feet) and lost approximately
90 percent of its area.

Consecutive droughts, agricultural water use, and dam construction on
rivers feeding the lake have contributed to the decline.

A shrinking Lake Urmia has implications for ecological and human health.
The lake, its islands, and surrounding wetlands comprise valuable
habitat and are recognized as a UNESCO Biosphere Reserve, Ramsar site,
and national park.

The area provides breeding grounds for waterbirds such as flamingos,
white pelicans, and white-headed ducks, as well as a stopover for
migratory species. However, with low lake levels, what water remains
becomes more saline and taxes the populations of brine shrimp and other
food sources for larger animals.

A shrinking lake also increases the likelihood of dust from the exposed
lakebed becoming swept up by winds and degrading air quality. Recent
studies have linked the low water levels in Lake Urmia with respiratory
health impacts among the local population. The relative effects of
climate, water usage, and dams on Lake Urmia's water level is a topic of
debate. The lake did see some recovery during a 10-year restoration
program beginning in 2013.

However, the efficacy of that effort has been difficult to parse since
strong rains also fell during that period. Some research has concluded
that climatic factors were primarily responsible for the recovery.

The deep-blue sea is turning a touch greener. While that may not seem as
consequential as, say, record warm sea surface temperatures, the color
of the ocean surface is indicative of the ecosystem that lies beneath.
Communities of phytoplankton, microscopic photosynthesizing organisms,
abound in near-surface waters and are foundational to the aquatic food
web and carbon cycle.

This shift in the water's hue confirms a trend expected under climate
change and signals changes to ecosystems within the global ocean, which
covers 70 percent of Earth's surface. Researchers led by B. B. Cael, a
principal scientist at the U.K.'s National Oceanography Centre, revealed
that 56 percent of the global sea surface has undergone a significant
change in color in the past 20 years.

After analyzing ocean color data from the MODIS (Moderate Resolution
Imaging Spectroradiometer) instrument on NASA's Aqua satellite, they
found that much of the change stems from the ocean turning more green.
The map above highlights the areas where ocean surface color changed
between 2002 and 2022, with darker shades of green representing
more-significant differences (higher signal-to-noise ratio). By
extension, said Cael, "these are places we can detect a change in the
ocean ecosystem in the last 20 years."

The study focused on tropical and subtropical regions, excluding higher
latitudes, which are dark for part of the year, and coastal waters,
where the data are naturally very noisy. The black dots on the map
indicate the area, covering 12 percent of the ocean's surface, where
chlorophyll levels also changed over the study period.

Chlorophyll has been the go-to measurement for remote sensing scientists
to gauge phytoplankton abundance and productivity. However, those
estimates use only a few colors in the visible light spectrum. The
values shown in green are based on the whole gamut of colors and
therefore capture more information about the ecosystem as a whole. A
long time series from a single sensor is relatively rare in the remote
sensing world. As the Aqua satellite was celebrating its 20th year in
orbit in 2022---far exceeding its design life of 6 years---Cael wondered
what long term trends could be discovered in the data. In particular, he
was curious what might have been missed in all the ocean color
information it had collected. "There's more encoded in the data than we
actually make use of," he said.

By going big with the data, the team discerned an ocean color trend that
had been predicted by climate modeling, but one that was expected to
take 30-40 years of data to detect using satellite-based chlorophyll
estimates. That's because the natural variability in chlorophyll is high
relative to the climate change trend. The new method, incorporating all
visible light, was robust enough to confirm the trend in 20 years. At
this stage, it is difficult to say what exact ecological changes are
responsible for the new hues. However, the authors posit, they could
result from different assemblages of plankton, more detrital particles,
or other organisms such as zooplankton.

It is unlikely the color changes come from materials such as plastics or
other pollutants, said Cael, since they are not widespread enough to
register at large scales. "What we do know is that in the last 20 years,
the ocean has become more stratified," he said. Surface waters have
absorbed excess heat from the warming climate, and as a result, they are
less prone to mixing with deeper, more nutrient-rich layers.

This scenario would favor plankton adapted to a nutrient-poor
environment. The areas of ocean color change align well with where the
sea has become more stratified, said Cael, but there is no such overlap
with sea surface temperature changes. More insights into Earth's aquatic
ecosystems may soon be on the way.

NASA's PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite, set
to launch in 2024, will return observations in finer color resolution.
The new data will enable researchers to infer more information about
ocean ecology, such as the diversity of phytoplankton species and the
rates of phytoplankton growth.

On September 10, 2023, a low-pressure storm brought heavy rains to
northeastern Libya, causing deadly flooding and devastation in cities
along the Mediterranean coast. On the coast of Libya's Cyrenaica region,
Al Bayda recorded 414 millimeters (16 inches) of rain in one day.

Nearby, the port city of Derna received more than 100 millimeters (4
inches) over the course of the storm---far exceeding the city's average
monthly rainfall for September of less than 1.5 millimeters (0.1
inches). Derna lies at the end of a long, narrow valley, called a wadi,
which is dry for most of the year.

Floods triggered two dams along Wadi Derna to collapse, sending
floodwater and mud to the city. According to news reports, floodwater
swept away roads and entire neighborhoods. The images above show the
Cyrenaica region before and after the storm. They are false color, which
makes water (blue) stand out from the surroundings. The image on the
right, acquired on September 13, shows water filling low-lying areas and
wadis inland from the coast.

The image on the left shows the same area on September 7. Both images
were acquired with the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA's Terra satellite. The flooding and damage in Derna is
difficult to see at this resolution, although sediment flowing into the
Mediterranean is visible in natural color images.

In the days prior to making landfall in Libya, the same low-pressure
storm (named Storm Daniel by the Hellenic National Meteorological
Service) swamped parts of Greece, Turkey, and Bulgaria. As the storm
approached Libya, it developed characteristics of a tropical-like
cyclone, or "medicane," with winds measuring around 70 to 80 kilometers
(43 to 50 miles) per hour.

The natural-color image above, acquired with MODIS on NASA's Terra
satellite, shows the storm on September 10 as it made landfall in
northeastern Libya. Only one or two medicanes typically develop in a
year, according to NOAA.

As of September 13, authorities were still conducting search and rescue
operations in the region. Derna was still largely inaccessible on that
day, making it difficult to assess the full impact of the flood.

Sea surface temperatures have a large influence on climate and weather.
For example, every 3 to 7 years a wide swath of the Pacific Ocean along
the equator warms by 2 to 3 degrees Celsius.

This warming is a hallmark of the climate pattern El Niño, which changes
rainfall patterns around the globe, causing heavy rainfall in the
southern United States and severe drought in Australia, Indonesia, and
southern Asia.

On a smaller scale, ocean temperatures influence the development of
tropical cyclones (hurricanes and typhoons), which draw energy from warm
ocean waters to form and intensify.

These sea surface temperature maps are based on observations by the
Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua
satellite. The satellite measures the temperature of the top millimeter
of the ocean surface. In this map, the coolest waters appear in blue
(approximately -2 degrees Celsius), and the warmest temperatures appear
in pink-yellow (35 degrees Celsius).

Landmasses and the large area of sea ice around Antarctica appear in
shades of gray, indicating no data were collected.

The most obvious pattern shown in the time series is the year-round
difference in sea surface temperatures between equatorial regions and
the poles.

Various warm and cool currents stand out even in monthly averages of sea
surface temperature. A band of warm waters snakes up the East Coast of
the United States and veers across the North Atlanticâ€"the Gulf Stream.

Although short-lived weather events that influence ocean temperature are
often washed out in monthly averages, a few events show up.

For example, in December 2003, strong winds blew southwest from the Gulf
of Mexico over Central America toward the Pacific Ocean, driving surface
waters away from the coast, and allowing cold water from deeper in the
ocean to well up to the surface. These winds are a recurring phenomenon
in the area in the winter; they are known as Tehuano winds.

At the base of the ocean food web are single-celled algae and other
plant-like organisms known as phytoplankton. Like plants on land,
phytoplankton use chlorophyll and other light-harvesting pigments to
carry out photosynthesis, absorbing atmospheric carbon dioxide to
produce sugars for fuel. Chlorophyll in the water changes the way it
reflects and absorbs sunlight, allowing scientists to map the amount and
location of phytoplankton. These measurements give scientists valuable
insights into the health of the ocean environment, and help scientists
study the ocean carbon cycle.

These chlorophyll maps show milligrams of chlorophyll per cubic meter of
seawater each month. Places where chlorophyll amounts were very low,
indicating very low numbers of phytoplankton are blue. Places where
chlorophyll concentrations were high, meaning many phytoplankton were
growing, are dark green. The observations come from the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite.
Land is dark gray, and places where MODIS could not collect data because
of sea ice, polar darkness, or clouds are light gray.

The highest chlorophyll concentrations, where tiny surface-dwelling
ocean plants are thriving, are in cold polar waters or in places where
ocean currents bring cold water to the surface, such as around the
equator and along the shores of continents. It is not the cold water
itself that stimulates the phytoplankton. Instead, the cool temperatures
are often a sign that the water has welled up to the surface from deeper
in the ocean, carrying nutrients that have built up over time. In polar
waters, nutrients accumulate in surface waters during the dark winter
months when plants can't grow. When sunlight returns in the spring and
summer, the plants flourish in high concentrations.

A band of cool, plant-rich waters circles the globe at the Equator, with
the strongest signal in the Atlantic Ocean and the open waters of the
Pacific Ocean. This zone of enhanced phytoplankton growth comes from the
frequent upwelling of cooler, deeper water as a result of the dominant
easterly trade winds blowing across the ocean surface. In many coastal
areas, the rising slope of the sea floor pushes cold water from the
lowest layers of the ocean to the surface. The rising, or upwelling
water carries iron and other nutrients from the ocean floor. Cold
coastal upwelling and subsequent phytoplankton growth are most evident
along the west coasts of North and South America and southern Africa.

In March and April 2023, some earth scientists began to point out that
average sea surface temperatures had surpassed the highest levels seen
in a key data record maintained by NOAA. Months later, they remain at
record levels, with global sea surface temperatures 0.99°C (1.78°F)
above average in July. That was the fourth consecutive month they were
at record levels. Scientists from NASA have taken a closer look at why.
"There are a lot of things that affect the world's sea surface
temperatures, but two main factors have pushed them to record heights,"
said Josh Willis, an oceanographer at NASA's Jet Propulsion Laboratory
(JPL). "We have an El Niño developing in the Pacific, and that's on top
of long-term global warming that has been pushing ocean temperatures
steadily upward almost everywhere for a century."

The map above shows sea surface temperature anomalies on August 21,
2023, when many areas were more than 3°C (5.4°F) warmer than normal. On
that date, much of the central and eastern regions of the equatorial
Pacific were unusually warm, the signature of a developing El Niño. As
has been the case for weeks, large patches of warm water were also
present in the Northwest Pacific near Japan and the Northeast Pacific
near California and Oregon. Portions of the Indian, Southern, and Arctic
Oceans also showed unusual warmth.

The map is based on data from the Multiscale Ultrahigh Resolution Sea
Surface Temperature (MUR SST) project, a JPL effort that blends
measurements of sea surface temperatures from multiple NASA, NOAA, and
international satellites, as well as ship and buoy observations. Rather
than showing absolute temperature, the anomaly reflects the difference
between the sea surface temperature on August 21, 2023, and the
2003-2014 average for that day. The video below, also based on MUR SST
data, shows global sea surface temperatures since April 1, 2023, the
period when they have been at record-breaking levels. The warmest waters
appear dark red.

In March and April 2023, some earth scientists began to point out that
average sea surface temperatures had surpassed the highest levels seen
in a key data record maintained by NOAA. Months later, they remain at
record levels, with global sea surface temperatures 0.99°C (1.78°F)
above average in July.

That was the fourth consecutive month they were at record levels.
Scientists from NASA have taken a closer look at why. "There are a lot
of things that affect the world's sea surface temperatures, but two main
factors have pushed them to record heights," said Josh Willis, an
oceanographer at NASA's Jet Propulsion Laboratory (JPL). "We have an El
Niño developing in the Pacific, and that's on top of long-term global
warming that has been pushing ocean temperatures steadily upward almost
everywhere for a century."

The map above shows sea surface temperature anomalies on August 21,
2023, when many areas were more than 3°C (5.4°F) warmer than normal. On
that date, much of the central and eastern regions of the equatorial
Pacific were unusually warm, the signature of a developing El Niño.

As has been the case for weeks, large patches of warm water were also
present in the Northwest Pacific near Japan and the Northeast Pacific
near California and Oregon. Portions of the Indian, Southern, and Arctic
Oceans also showed unusual warmth. The map is based on data from the
Multiscale Ultrahigh Resolution Sea Surface Temperature (MUR SST)
project, a JPL effort that blends measurements of sea surface
temperatures from multiple NASA, NOAA, and international satellites, as
well as ship and buoy observations. Rather than showing absolute
temperature, the anomaly reflects the difference between the sea surface
temperature on August 21, 2023, and the 2003-2014 average for that day.

The video below, also based on MUR SST data, shows global sea surface
temperatures since April 1, 2023, the period when they have been at
record-breaking levels. The warmest waters appear dark red.

"Over the long term, we're seeing more heat and warmer sea surface
temperatures pretty much everywhere," said Gavin Schmidt, the director
of NASA's Goddard Institute for Space Studies. "That long-term trend is
almost entirely attributable to human forcing---the fact that we've put
such a huge amount of greenhouse gas in the atmosphere since the start
of the industrial era." Schmidt noted that other factors---such as
weather and wind patterns or the distribution of dust and
aerosols---have short-term effects on sea surface temperatures in
certain regions, but they generally have a minor effect on the
longer-term global mean. Previous research shows that as much as 90
percent of the excess heat that has occurred in recent decades due to
increasing greenhouse gas emissions is absorbed by the ocean, with much
of that heat stored near the surface. The most important factor that
helped push sea surface temperatures into record territory in 2023 was
the evolving El Niño in the Pacific, according to Willis. He came to
that conclusion by analyzing the timing and intensity of sea surface
temperature anomalies in several regions and comparing them to the
global trend. "We had a big jump in global surface temperature at the
beginning of April---exactly when the Pacific temperatures jumped up and
also when sea levels in the eastern Pacific started to rise," Willis
said. "The heat waves in the Atlantic are important and will have
serious effects on marine life and weather in Europe in the coming
months. But it's the Pacific that has taken the global mean on a wild
ride this year." What happens in the Pacific tends to have a large
influence on the global sea surface temperatures partly because of its
size.

The Pacific represents about half of the world's ocean area.

Marine heat waves---defined as periods of persistent anomalously warm
ocean temperatures (warmer than 90 percent of the previous observations
for a given time of year)---have occurred recently in several areas.

One NOAA analysis showed that 48 percent of the global oceans were in
the midst of a marine heat wave in August---a larger area than for any
other month since the start of the record in 1991.

Particularly intense events have warmed the North Atlantic and parts of
the Caribbean in recent months.

Willis expects the heat in the equatorial Pacific to have more staying
power than many of the other marine heat waves simmering around the
world. "Many of the marine heat waves we're seeing are ephemeral and
'skin' deep, generally lasting on the order of weeks and driven by
atmospheric forces," explained Willis.

The unusually warm water in the equatorial Pacific associated with the
developing El Niño after three consecutive years of La Niña is expected
to weaken trade winds in ways that reinforce and amplify the warming of
surface waters, fueling the El Niño further.

Forecasters from NOAA say that there is a greater than 95 percent chance
that El Niño conditions will persist throughout the Northern Hemisphere
winter.

"What's happening in the Pacific with El Niño will influence global
weather patterns and sea surface temperatures well into the winter and
possibly even longer," Willis said.

To monitor sea surface temperatures, scientists at NOAA and NASA analyze
observations from sensors and buoys in the oceans, ships, and several
different polar-orbiting and geostationary satellites. Groups of
scientists with NOAA's Physical Sciences Laboratory, NOAA's Coral Reef
Watch, and NASA's Jet Propulsion Laboratory track marine heat waves and
sea surface temperature anomalies closely.

You can use NASA's State of the Ocean Tool on Worldview to monitor daily
sea surface temperature anomalies.

One of the wettest wet seasons in northern Australia transformed large
areas of the country's desert landscape over the course of many months
in 2023. A string of major rainfall events that dropped 690 millimeters
(27 inches) between October 2022 and April 2023 made it the
sixth-wettest season on record since 1900--1901.

This series of false-color images illustrates the rainfall's months-long
effects downstream in the Lake Eyre Basin. Water appears in shades of
blue, vegetation is green, and bare land is brown. The images were
acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on
NASA's Terra satellite between January and July 2023.

In the January 22 image (left), water was coursing through seasonally
dry channels of the Georgina River and Eyre Creek following weeks of
heavy rains in northern Queensland. By April 21 (middle), floodwaters
had reached further downstream after another intense period of
precipitation in March. This scene shows that water had filled in some
of the north-northwest trending ridges that are part of a vast fossil
landscape of wind-formed dunes, while vegetation had emerged in wet soil
upstream. Then by July 26 (right), the riverbed had filled with even
more vegetation.

The Georgina River and Eyre Creek drain approximately 210,000 square
kilometers (81,000 square miles), nearly the area of the United Kingdom.
Visible in the lower part of the images, the lake gets refreshed about
every three years; when it reaches especially high levels, it may take
18 months to 2 years to dry up. Two smaller neighboring lakes flood
seasonally. These three lakes and surrounding floodplains support
hundreds of thousands of waterbirds and are designated as an Important
Bird Area.

Seasonal flooding is a regular occurrence in these desert river systems.
However, the events of the 2022-2023 rainy season stood out in several
ways. They occurred while La Niña conditions were in place over the
tropical Pacific Ocean. (The wettest seasons in northern Australia have
all occurred during La Niña years, according to Australia's Bureau of
Meteorology.) In addition, major rains occurring in succession, as was
the case with the January and March events, have the overall effect of
prolonging floods. That's because vegetation that grows after the first
event slows down the pulse of water that comes through in the next rain
event.

The high water has affected both local communities and ecosystems.
Floods have inundated cattle farms and isolated towns on temporary
islands. At the same time, they are a natural feature of the
"boom-and-bust" ecology of Channel Country, providing habitat and
nutrients that support biodiversity.

After three consecutive years of La Niña, spring 2023 saw the return of
El Niño---a natural climate phenomenon characterized by the presence of
warmer than normal sea surface temperatures (and higher sea levels) in
the central and eastern tropical Pacific Ocean.

El Niño is associated with the weakening of easterly trade winds and the
movement of warm water from the western Pacific toward the western coast
of the Americas. The phenomenon can have widespread effects, often
bringing cooler, wetter conditions to the U.S. Southwest and drought to
countries in the western Pacific, such as Indonesia and Australia.

Satellite- and ocean-based measurements of sea surface temperature are
one way to detect the arrival of El Niño. Its signature also shows up in
satellite measurements of sea surface height, which rises as ocean
temperatures warm up. That's because warmer water expands to fill more
volume, while cooler water contracts.

The map above depicts sea surface height anomalies across the central
and eastern Pacific Ocean as observed from June 1--10, 2023. Shades of
blue indicate sea levels that were lower than average; normal sea level
conditions appear white; and reds indicate areas where the ocean stood
higher than normal.

Data for the map were acquired by the Sentinel-6 Michael Freilich and
Sentinel-3B satellites and processed by scientists at NASA's Jet
Propulsion Laboratory (JPL). Note that signals related to seasonal
cycles and long-term trends have been removed to highlight sea level
anomalies associated with El Niño and other short-term natural
phenomena.

In a report released on June 8, 2023, the NOAA Climate Prediction Center
declared El Niño conditions were present. The report pointed to sea
surface temperatures in the Niño 3.4 region of the tropical Pacific
(from 170° to 120° West longitude) that in May 2023 were 0.8°C (1.4°F)
above the long-term average.

Forecasters expected El Niño conditions to gradually strengthen into the
2023--2024 Northern Hemisphere winter, by which time they called for a
84 percent chance of a moderate strength El Niño developing and a 56
percent chance of a strong El Niño.

As of June 2023, however, El Niño was not as far along as past El Niño
events by the same time of year, according to Josh Willis, an
oceanographer and Sentinel-6 Michael Freilich project scientist at JPL.

"It's still a bit too early to say whether this will be a big one,"
Willis said. "It will probably have some global impacts, but there's
still time for this El Niño to underwhelm."

As spring turned to summer, phytoplankton came to life in the shallow
waters of the North Sea. Sunlight and warm ocean temperatures in June
2023 enabled the microscopic plant-like organisms to rapidly multiply
and form a dazzling turquoise display visible to satellites.

Satellites observed hints of the bloom developing between Scotland and
Norway for about two weeks, but the view from above was mostly hidden by
clouds. Then, mostly clear skies on the afternoon of June 15, 2023,
allowed the Visible Infrared Imaging Radiometer Suite (VIIRS) on the
NOAA-20 satellite to acquire this natural-color image of the abundant
phytoplankton.

Phytoplankton are to the ocean what plants are to land: primary
producers, an essential food source for other life, and the main carbon
recycler for the marine environment. Diatoms, coccolithophores, algae,
and other forms of phytoplankton are floating, plant-like organisms that
soak up sunshine, carbon dioxide, and nutrients to create their own
energy.

This bloom might contain some diatoms---a type of phytoplankton with
silica shells and ample chlorophyll that color the surface waters green.
The color of the water, however, indicates that coccolithophores are
likely abundant. Coccolithophores have calcium carbonate shells that
make the water appear milky blue in satellite imagery, and they
typically peak in abundance at these latitudes around the summer
solstice.

Phytoplankton are typically most abundant in the North Sea in late
spring and early summer when high levels of nutrients are available in
the water. Melting sea ice and increased runoff from European rivers---a
product of melting snow and spring rains---carry a heavy load of
nutrients out to sea. Intense seasonal winds blowing over the relatively
shallow sea also cause a lot of mixing that brings nutrients to the
surface.

Researchers in Norway studied the patterns and timing of phytoplankton
blooms in the North Sea using data from multiple satellite sensors,
including VIIRS and NASA's Moderate Resolution Imaging Spectroradiometer
(MODIS). They found that between 2000 and 2020, blooms in this region of
the North Sea peaked in mid-to-late April. These blooms lasted, on
average, about 46 days. They also found that in the 21-year study
period, phytoplankton blooms in the region were starting later in the
year and lasting slightly longer. The cause of this delay, however, was
not immediately clear.

The composition of phytoplankton blooms near Norway may be changing over
time with warmer sea surface temperatures, the researchers noted, but it
is difficult to tell the species composition of blooms without taking
physical samples. However, a future NASA Plankton, Aerosol, Cloud, ocean
Ecosystem (PACE) satellite mission will enable researchers to infer more
information about ocean ecology, such as the species of phytoplankton
present in blooms and the rates of phytoplankton growth.

Sea ice in the Sea of Okhotsk put on a dazzling display in late May
2023, as the winter's ice pack thinned and broke up. The freely drifting
ice, subject to wind and currents, formed a series of spirals off the
coast of Russia.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua
satellite captured this image on May 28, 2023. More-intact ice is
visible on the north side of the P'yagina Peninsula (Poluostrov
P'yagina), at the top of the image, with smaller pieces breaking away
and drifting to the south and west. A group of islands---too small to
see clearly at this scale---off the eastern tip of the land may be
responsible for the small eddies in that area. Spirals such as these can
form downstream of a stationary object that obstructs fluid flow.

The Sea of Okhotsk, which is hemmed in by the Siberian coast and the
Kamchatka Peninsula, is the southernmost sea in the Northern Hemisphere
that freezes seasonally. An influx of frigid Siberian air, in addition
to inflows of freshwater from rivers that lower the salinity and raise
the freezing point of the water, create conducive conditions for ice to
form during the colder months.

During the 2022-2023 winter, the extent of sea ice in the Arctic was
below average. The end-of-winter minimum extent, reached on March 6, was
the sixth lowest in the satellite record, according to data maintained
by the National Snow & Ice Data Center (NSIDC). The NSIDC also noted
that seasonal ice decline picked up in the last several days of May,
when this image was captured.

In a recent study, researchers in Japan found that yearly differences in
ice extent are largely governed by regional cold air masses and
low-pressure systems, along with large-scale patterns associated with
the El Niño/Southern Oscillation (ENSO). Looking at longer term
climate-driven trends, they reported that ice extent in the Sea of
Okhotsk decreased by about 9 percent per decade between 1979 and 2010.

Every fall, millions of people flock to the Shuangtaizi Estuary (also
called the Liao River Estuary) in northeastern China to marvel at its
brilliant red coastal landscapes. They are drawn by the expanses of rare
salt-loving seepweed that thrive in the estuary's alkaline tidal
mudflats.

The small shrubby plants, Suaeda salsa (also called Suaeda heteroptera),
start out greenish-red in the spring but become a bright crimson in fall
as seasonal shifts in rainfall and tides expose seepweed to slightly
saltier, cooler conditions. This leads to the increased production and
accumulation of the red pigment betalain.

However, the estuary has changed significantly in recent decades due to
coastal development, raising questions about the long-term viability of
its colorful seepweed beaches and wetland habitat. The scale of change
is apparent in the pair of Landsat images shown above.

The image on the left, acquired by the Thematic Mapper on Landsat 5,
shows the estuary in 1986; the image on the right, from the Operational
Land Imager-2 (OLI-2) on Landsat 9, shows the same area in 2022. Both
images were acquired in September, around the time when seepweed reaches
its deepest red. The green areas along the river are dominated by
Phragmites australis, a type of reed. The yellow areas are rice fields.
The photo below shows seepweed (red) in the foreground transitioning
into Phragmites australis (green) in the background. Large new
aquaculture facilities---and a new port (lower right of image)---have
replaced tidal flats where seepweed once thrived. The construction of a
dyke and reservoir on the eastern bank of the river has also isolated
part of the estuary from tidal waters, making the area unsuitable for
seepweed. In wider views of the 1986 and 2022 images, notice how
seepweed was further constrained by urbanization and the expansion of
aquaculture to the east of the port, as well as the expansion of gas and
oil drilling on the western bank of the Shuangtaizi River.

Human activities have affected seepweed in other less direct ways in
recent decades. The construction of dams, bridges, and canals caused
spikes in the amount of sediment carried by the river and deposited on
tidal flats downstream. The extra accumulations made it difficult for
new seepweed plants to germinate in some areas. Researchers have also
found evidence indicating that the construction of boardwalks and the
rising number of tourists has harmed seepweed by scaring away waterbirds
that feed on crabs, leading to higher numbers of crabs grazing on
seepweed in certain areas.

Overall, hundreds of square kilometers of wetlands have been lost since
the 1980s, according to one analysis that spans three decades of Landsat
observations. The amount of land with seepweed dropped by roughly 25
percent during that time, though certain parts of the estuary have seen
seepweed areas expand or grow more concentrated.

Seepweed-seeking tourists are not the only group affected by the loss of
tidal flats and wetlands in this area. The estuary provides habitat for
more than 100 water birds, including the critically endangered Siberian
Crane (Leucogeranus leucogeranus), the endangered Oriental stork
(Ciconia boyciana), and the red-crowned Crane (Grus japonensis). The
estuary was named a national nature reserve in 1998 and a Ramsar site in
2005.

For the past few decades, scientists have been observing natural ocean
fertilization events---episodes when plumes of volcanic ash, glacial
flour, wildfire soot, and desert dust blow out onto the sea surface and
spur massive blooms of phytoplankton. But beyond these extreme events,
there is a steady, long-distance rain of dust particles onto the ocean
that promotes phytoplankton growth just about all year and in nearly
every basin.

In a new study published May 5 in the journal Science, a team of
researchers from Oregon State University, the University of Maryland
Baltimore County, and NASA combined satellite observations with an
advanced computer model to home in on how mineral dust from land
fertilizes the growth of phytoplankton in the ocean. Phytoplankton are
microscopic, plant-like organisms that form the center of the marine
food web.

Phytoplankton float near the ocean surface primarily subsisting on
sunlight and mineral nutrients that well up from the depths or float out
to sea in coastal runoff. But mineral-rich desert dust---borne by strong
winds and deposited in the ocean---also plays an important role in the
health and abundance of phytoplankton.

This image, acquired on April 8, 2011, by the Moderate Resolution
Imaging Spectroradiometer (MODIS) on NASA's Terra satellite, shows
Saharan dust over the Bay of Biscay. A phytoplankton bloom in the bay
makes the water appear bright green and blue. Sediment is likely
contributing to some of the color, especially in areas closer to the
shore.

According to the new study, dust deposition onto the ocean supports
about 4.5 percent of yearly global export production---a measure of how
much of the carbon phytoplankton take up during photosynthesis sinks
into the deep ocean. However, this contribution approaches 20 percent to
40 percent in some ocean regions at middle and higher latitudes.

Phytoplankton play a large role in Earth's climate and carbon cycle.
Like land plants, they contain chlorophyll and derive energy from
sunlight through photosynthesis. They produce oxygen and sequester a
tremendous amount of carbon dioxide in the process, potentially on a
scale comparable to rainforests. And they are at the bottom of an
ocean-wide food pecking order that ranges from tiny zooplankton to fish
to whales.

Dust particles can travel thousands of miles before falling into the
ocean, where they nourish phytoplankton long distances from the dust
source, said study coauthor Lorraine Remer, a research professor at the
University of Maryland Baltimore County. "We knew that atmospheric
transport of desert dust is part of what makes the ocean 'click,' but we
didn't know how to find it," she said.

Seasonal allergy sufferers be warned: this story may have you reaching
for the antihistamines. Researchers have determined that "slicks" on the
surface of the Baltic Sea, visible in satellite images, are made up of
pine pollen.

Pollen slicks are visible in these images of the Baltic Sea, acquired on
May 16, 2018, with the MultiSpectral Instrument (MSI) on the European
Space Agency's Sentinel-2A satellite. The images are false-color (bands
8A, 3, and 2) and have been enhanced to increase the visibility of the
pollen. The patterns are caused by wind-driven currents and waves moving
the pollen around on the surface of the water.

The composition of slicks in this region was previously unclear. Other
types of floating material, such as cyanobacteria and marine debris,
have been known to appear in satellite imagery. But by combining
experimental results, ground-based observations, and satellite image
processing, the researchers could confidently attribute the material in
the eddies to pine (Pinus sylvestris) pollen.

The impetus for investigating this phenomenon came from a different
marine event, said Chuanmin Hu, an ocean optics expert at the University
of South Florida who led the research. "This work is inspired by a
recent sea snot event in the Marmara Sea that created a huge problem for
Türkiye and its coastal regions," he said. Sea snot, which is caused by
phytoplankton releasing a gooey substance, coated large swaths of the
sea in May 2021 and caught Hu's attention when it was detected by
satellites.

That led him to wonder if anything comparable was occurring on other
large bodies of water nearby. As it turned out, satellite images of the
Baltic Sea from that time looked similar to the satellite images of sea
snot in the Marmara Sea (to human eyes, at least). But Hu found it
strange that there were no reports of disruptive slime from the large,
heavily trafficked sea.

To identify potential slicks, Hu and colleagues inspected
medium-resolution satellite images from sensors such as the Moderate
Resolution Imaging Spectroradiometer on NASA's Terra and Aqua
satellites. When his team analyzed other satellite data for the spectral
signature of the mystery Baltic Sea substance, they realized it was
distinct from sea snot and other floating matter. The spectral shape had
a characteristically sharp increase between wavelengths of 400 and 500
nanometers.

Given the timing of the slicks and the prevalence of pine trees in the
nine countries surrounding the sea, they suspected pollen as a possible
culprit. Collaborators in Poland had photographs of pollen on the
surface of the water, acquired during fieldwork in May 2013 (below). To
dig deeper, the U.S. and Polish groups conducted laboratory and field
experiments to measure the spectral reflectance of pollen. Indeed, the
results matched what was captured by satellites.

The researchers then looked back at springtime images of the Baltic Sea
from 2000 to 2021 and saw similar slick patterns in 14 of those years.
Notably, the pollen's footprint on the sea in the second half of the
study period was markedly larger than in the first half. In recent
years, slicks often cover some portion of the sea in parts of May and
June.

This observation aligns with trends toward longer pollen seasons and
more pollen production that have been documented in other areas of the
world. For example, one recent study found that pollen season in North
America starts nearly three weeks sooner and lasts about a week longer
than it did in 1990, driven by warming temperatures. In addition, more
carbon dioxide in the atmosphere fueling photosynthesis may increase
plants' potential to produce more pollen.

The profusion of pollen may have larger impacts beyond making people
sneeze. Though not well studied, pollen grains can affect aquatic
ecosystems by supplying carbon to the sea. Much like leaf litter
supports food webs in lakes and streams, pollen grains may be an
important source of nutrients for insect larvae, crustaceans, and other
invertebrates in coastal Baltic Sea waters.

Having cracked the code of distinguishing pollen in satellite imagery,
Hu thinks the imagery may lead to several new insights. "If we can track
pollen aggregation in different places, this may provide useful data for
fisheries studies," he said. Even more, the technique could complement
land-based air quality sensors to monitor allergens---all the more
relevant as human health impacts from allergies intensify.

For several weeks in April 2023, swirls of green and turquoise grew more
vibrant in the waters off the Mid-Atlantic coast of the United States.
Some of the color is due to an abundance of phytoplankton. Though each
of these floating plant-like organisms is microscopic, large groups of
them are visible to satellites.

A phytoplankton bloom was under way on April 20, 2023, when the Moderate
Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite
acquired this image (top). The detailed image below was acquired the
same day with the Operational Land Imager-2 (OLI-2) on Landsat 9.

Phytoplankton are responsible for nearly half of Earth's primary
production. They turn carbon dioxide, sunlight, and nutrients into the
food that feeds almost all other life in the sea, from zooplankton to
finfish to whales.

The type of phytoplankton present in the bloom cannot be definitively
identified based on these natural-color images. But assessments of past
blooms in the area have turned up a mix of diatoms and coccolithophores.
Diatoms, a microscopic form of algae, have silica shells and plenty of
chlorophyll that can make the water appear green. Coccolithophores have
chalky calcium carbonate plates (coccoliths) that reflect light and can
make the water appear bright blue.

Color can also come from other sources, such as sediment or colored
dissolved organic matter (CDOM) that have mixed in the water. Discharge
from the Delaware River delivers sediment and CDOM to the coastal waters
in this region. It can also supply nutrients---contained in the runoff
from farms and urban and suburban areas---that help to fuel large
blooms.

Similar blooms have occurred in recent years, in both 2021 and 2022.
Those blooms, however, developed their most striking colors almost one
month later, around mid-May.

In February 2023, Tropical Cyclone Gabrielle churned south across the
Coral Sea and passed over the Bellona Plateau---a shallow area 600
kilometers (400 miles) west of Grande Terre, the principal island of New
Caledonia. Once a sizable island during the Pleistocene ice ages, the
plateau is now submerged under 25-50 meters of water. It hosts reefs
that teem with corals, coralline algae, mollusks, foraminifera, and many
other types of marine life with calcium carbonate skeletons or shells.

Signs of underwater reefs and carbonate platforms are often subtle in
satellite imagery. But Gabrielle's winds were fierce enough that the
storm left a clear sign of the carbonate ecosystem below the water. The
passing storm stirred up enough carbonate sediment to temporarily
discolor more than 13,000 square kilometers of water, an area about the
size of Puerto Rico. Resuspension events of this size are rare at
Bellona Plateau, with this being only the second time it has happened at
this scale since the launch of the MODIS sensor on the Terra satellite
in 1999.

Gabrielle was passing over the area on February 9, 2023, when the
Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra
satellite acquired the first image above. After the storm clouds
cleared, the satellite observed carbonate sediment that had become
suspended in the water (second image) on February 11, 2023. The sediment
drifted in ocean currents over the span of a week, with water over the
Bellona plateau returning to its normal color by February 20, 2023.

The Operational Land Imager-2 (OLI-2) on Landsat 9 captured the detailed
images (below) showing sediment swirling in eddies around the plateau on
February 12, 2023. The sediment was likely fine-grained carbonate mud
with some larger carbonate sand mixed in. It likely formed due to the
erosion and accumulation of bits of coral skeletons, coralline algae,
and the hard shells of marine organisms that live on the plateau.

"With the right water chemistry and amount of light, plateaus like this
become major calcium carbonate factories," explained James Acker, an
oceanographer with ADNET Systems at the Goddard Earth Sciences Data and
Information Services Center (GES DISC). Previous estimates suggest that
although shallow coastal areas cover just 7 percent of the ocean's area,
they generate about half of the world's marine carbonate sediment.

Acker has been using satellites to observe carbonate resuspension events
since the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS)
in 1997. The goal is to develop better estimates for how much carbonate
sediment from shallow areas ends up getting pushed into deeper waters by
winds, currents, or other processes.

"Deep ocean water dissolves carbonate muds and sands when they sink,"
explained Acker. "That can help counter the ongoing ocean acidification
we're seeing that is caused by the rising levels of carbon dioxide in
the atmosphere." In some cases, depending on the chemistry of the water,
carbonates dissolve at depths as shallow as 500 meters. In others, they
dissolve at depths closer to 4.5 kilometers.

Estimates suggest that oceans absorb about 30 percent of the carbon
dioxide that humans release into the atmosphere. Some of that carbon
gets incorporated into shells and sediment and eventually stored as
calcium carbonate in limestone and other sedimentary rocks, making
carbonate platforms and marine sedimentary rock an important carbon
sink.

However, the estimates for how much carbonate these shallow carbonate
reefs and plateaus produce, export, and store vary significantly. And
there is considerable uncertainty about how the ocean's ability to store
carbon will change as the acidity of the ocean changes. More acidic
ocean waters make it harder for many marine organisms to build calcium
carbonate shells and thrive, so acidification may reduce how much carbon
ends up stored in sedimentary rocks.

The first step to investigating how climate change might be changing the
marine carbon cycle is to simply understand and document how much
carbonate sediment is cycling between shallow and deep water, explained
Acker. That has led Acker and sedimentologist Jude Wilber to examine
decades of satellite data to find out if storm and wind events play an
important role in this cycling from shallow to deep.

At the American Geophysical Union's Oceans meeting in 2022, Acker and
colleagues presented an analysis of a previous resuspension event that
followed Tropical Cyclone Wati hitting the Bellona Plateau in 2006. That
event occurred after the Category 4 storm stalled over the plateau for
two days and battered it with winds that exceeded 209 kilometers (135
miles) per hour.

However, the estimates for how much carbonate these shallow carbonate
reefs and plateaus produce, export, and store vary significantly. And
there is considerable uncertainty about how the ocean's ability to store
carbon will change as the acidity of the ocean changes. More acidic
ocean waters make it harder for many marine organisms to build calcium
carbonate shells and thrive, so acidification may reduce how much carbon
ends up stored in sedimentary rocks.

The first step to investigating how climate change might be changing the
marine carbon cycle is to simply understand and document how much
carbonate sediment is cycling between shallow and deep water, explained
Acker. That has led Acker and sedimentologist Jude Wilber to examine
decades of satellite data to find out if storm and wind events play an
important role in this cycling from shallow to deep.

At the American Geophysical Union's Oceans meeting in 2022, Acker and
colleagues presented an analysis of a previous resuspension event that
followed Tropical Cyclone Wati hitting the Bellona Plateau in 2006. That
event occurred after the Category 4 storm stalled over the plateau for
two days and battered it with winds that exceeded 209 kilometers (135
miles) per hour.

"Due to decades of satellite observations---and dramatic examples like
this---we can say confidently that tropical cyclones play a very
important role," said Acker. "Nothing else exports the volume of
sediment into deeper water that they do. The next step is to demonstrate
that in a more systematic and rigorous way by analyzing the entire
satellite record with machine learning techniques and getting teams out
in the field to better understand the dynamics of transport events."

Water from recent winter storms is needed by farmers, wildlife, and
residents in the region, where precipitation and lake levels in recent
years have been among the lowest since the 1970s. However, scientists
caution that similar large precipitation events in the past have not
been enough to reverse the longer-term depletion of groundwater---a
reserve of water that supplements surface sources used for irrigation
and other purposes.

"The abundant water is expected to recharge the groundwater in the next
few months, as we have seen during similar events in 2011 and 2017,"
said Pang-Wei Liu, a scientist at NASA's Goddard Space Flight Center.
"However, if the climate pattern is the same as before---dry and hot in
summer followed by low precipitation---and the water demands are still
high, then we expect the groundwater drawdown will continue."

The chart above, produced with data provided by Liu, shows a downward
trend in California's terrestrial water storage (dark blue line)
spanning nearly two decades. This includes surface and groundwater, and
water held within the soil and in snow. The rest of the lines show why
this is happening; amid some variability in all types of stored water,
it is groundwater (light blue line) that is sharply decreasing.

Liu and colleagues used data from the Gravity Recovery and Climate
Experiment (GRACE) and GRACE Follow-On satellite missions to show that
the depletion of groundwater in California's Central Valley has been
accelerating since 2003. Their results were published December 2022 in
Nature Communications.

"Even the wettest wet seasons are simply never enough to make up for the
far greater amount of groundwater that California extracts each year,"
said Jay Famiglietti, a global futures professor at Arizona State
University and a co-author of the paper. "Hopefully California's
Sustainable Groundwater Management Act can slow what will otherwise be a
speedy trip to the bottom."

Earth's average surface temperature in 2022 tied with 2015 as the fifth
warmest on record, according to an analysis by NASA. Continuing the
planet's long-term warming trend, global temperatures in 2022 were 0.89
degrees Celsius (1.6 degrees Fahrenheit) above the average for NASA's
baseline period (1951--1980), according to scientists at NASA's Goddard
Institute for Space Studies (GISS).

The past nine years have been the warmest years since modern
recordkeeping began in 1880. This means Earth in 2022 was about 1.11°C
(2°F) warmer than the late 19th century average.

The map above depicts global temperature anomalies in 2022. It does not
show absolute temperatures; instead, it shows how much warmer or cooler
each region of Earth was compared to the average from 1951 to 1980. The
bar chart below shows 2022 in context with temperature anomalies since
1880. The values represent surface temperatures averaged over the entire
globe for the year.

"The reason for the warming trend is that human activities continue to
pump enormous amounts of greenhouse gases into the atmosphere, and the
long-term planetary impacts will also continue," said Gavin Schmidt,
director of GISS, NASA's leading center for climate modeling.

Human-driven greenhouse gas emissions have rebounded following a
short-lived dip in 2020 due to the COVID-19 pandemic. Recently, NASA
scientists, as well as international scientists, determined carbon
dioxide emissions were the highest on record in 2022. NASA also
identified some super-emitters of methane---another powerful greenhouse
gas---using the Earth Surface Mineral Dust Source Investigation (EMIT)
instrument that launched to the International Space Station last year.

The Arctic region continues to experience the strongest warming
trends---close to four times the global average---according to GISS
research presented at the 2022 annual meeting of the American
Geophysical Union, as well as a separate study.

Communities around the world are experiencing impacts scientists see as
connected to the warming atmosphere and ocean. Climate change has
intensified rainfall and tropical storms, deepened the severity of
droughts, and increased the impact of storm surges. Last year brought
torrential monsoon rains that devastated Pakistan and a persistent
megadrought in the U.S. Southwest. In September, Hurricane Ian became
one of the strongest and costliest hurricanes to strike the continental
U.S.

NASA's global temperature analysis is drawn from data collected by
weather stations and Antarctic research stations, as well as instruments
mounted on ships and ocean buoys. NASA scientists analyze these
measurements to account for uncertainties in the data and to maintain
consistent methods for calculating global average surface temperature
differences for every year. These ground-based measurements of surface
temperature are consistent with satellite data collected since 2002 by
the Atmospheric Infrared Sounder on NASA's Aqua satellite and with other
estimates.

NASA uses the period from 1951--1980 as a baseline to understand how
global temperatures change over time. That baseline includes climate
patterns such as La Niña and El Niño, as well as unusually hot or cold
years due to other factors, ensuring it encompasses natural variations
in Earth's temperature.

Many factors can affect the average temperature in any given year. For
example, 2022 was one of the warmest on record despite a third
consecutive year of La Niña conditions in the tropical Pacific Ocean.
NASA scientists estimate that La Niña's cooling influence may have
lowered global temperatures slightly (about 0.06°C or 0.11°F) from what
the average would have been under more typical ocean conditions.

A separate, independent analysis by the National Oceanic and Atmospheric
Administration (NOAA) concluded that the global surface temperature for
2022 was the sixth highest since 1880. NOAA scientists use much of the
same raw temperature data in their analysis and have a different
baseline period (1901--2000) and methodology. Although rankings for
specific years can differ slightly between the records, they are in
broad agreement and both reflect ongoing long-term warming.


The water cycle is often taught as a simple circular cycle of evaporation,
condensation, and precipitation. Although this can be a useful model,
the reality is much more complicated. The paths and influences of water
through Earth’s ecosystems are extremely complex and not completely understood.
NOAA is striving to expand understanding of the water cycle at global to local
scales to improve our ability to forecast weather, climate, water resources,
and ecosystem health.

The water cycle on Earth

Water is essential to life on Earth. In its three phases (solid, liquid, and gas),
water ties together the major parts of the Earth’s climate system — air,
clouds, the ocean, lakes, vegetation, snowpack, and glaciersoffsite link.

The water cycle shows the continuous movement of water within the Earth
and atmosphere. It is a complex system that includes many different processes.
Liquid water evaporates into water vapor, condenses to form clouds, and
precipitates back to earth in the form of rain and snow. Water in different
phases moves through the atmosphere (transportation). Liquid water flows
across land (runoff), into the ground (infiltration and percolation),
and through the ground (groundwater). Groundwater moves into plants (plant uptake)
and evaporates from plants into the atmosphere (transpiration). Solid ice and snow
can turn directly into gas (sublimation). The opposite can also take place when
water vapor becomes solid (deposition).

The water cycle shows the continuous movement of water within the Earth and atmosphere.
It is a complex system that includes many different processes. Liquid water evaporates
into water vapor, condenses to form clouds, and precipitates back to earth in the form
of rain and snow. Water in different phases moves through the atmosphere (transportation).
Liquid water flows across land (runoff), into the ground (infiltration and percolation),
and through the ground (groundwater). Groundwater moves into plants (plant uptake) and
evaporates from plants into the atmosphere (transpiration). Solid ice and snow can turn
directly into gas (sublimation). The opposite can also take place when water vapor becomes
solid (deposition).

The water cycle, also known as the hydrologic cycle or the hydrological cycle,
is a biogeochemical cycle that describes the continuous movement of water on, above and below the
surface of the Earth. The mass of water on Earth remains fairly constant over time but the
partitioning of the water into the major reservoirs of ice, fresh water, saline water (salt water)
and atmospheric water is variable depending on a wide range of climatic variables.
The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the
atmosphere, by the physical processes of evaporation, transpiration, condensation, precipitation,
infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms:
liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86%
of global evaporation.

The water cycle involves the exchange of energy, which leads to temperature changes.
When water evaporates, it takes up energy from its surroundings and cools the environment.
When it condenses, it releases energy and warms the environment. These heat exchanges influence climate.

The evaporative phase of the cycle purifies water, causing
salts and other solids picked up during the cycle to be left behind, and then the
condensation phase in the atmosphere replenishes the land with freshwater.
The flow of liquid water and ice transports minerals across the globe. It is also involved in reshaping the
geological features of the Earth, through processes including erosion and sedimentation.
The water cycle is also essential for the maintenance of most life and ecosystems on the planet.

The water cycle is powered from the energy emitted by the sun. This energy heats water in the ocean and seas.
Water evaporates as water vapor into the air. Some ice and snow sublimates directly into water vapor.
Evapotranspiration is water transpired from plants and evaporated from the soil. The water molecule H2O
has smaller molecular mass than the major components of the atmosphere, nitrogen and oxygen
and hence is less dense. Due to the significant difference in density, buoyancy drives humid air higher.
As altitude increases, air pressure decreases and the temperature drops (see Gas laws).

The lower temperature causes water vapor to condense into tiny liquid water droplets which are
heavier than the air, and which fall unless supported by an updraft. A huge concentration of
these droplets over a large area in the atmosphere becomes visible as cloud, while condensation
near ground level is referred to as fog.

Atmospheric circulation moves water vapor around the globe; cloud particles collide, grow,
and fall out of the upper atmospheric layers as precipitation. Some precipitation falls as snow,
hail, or sleet, and can accumulate in ice caps and glaciers, which can store frozen water for thousands
of years. Most water falls as rain back into the ocean or onto land, where the water flows over the
ground as surface runoff. A portion of this runoff enters rivers, with streamflow moving water
towards the oceans. Runoff and water emerging from the ground (groundwater) may be stored as
freshwater in lakes. Not all runoff flows into rivers; much of it soaks into the ground as infiltration.
Some water infiltrates deep into the ground and replenishes aquifers, which can store freshwater for
long periods of time. Some infiltration stays close to the land surface and can seep back into surface-water
bodies (and the ocean) as groundwater discharge or be taken up by plants and transferred back to the
atmosphere as water vapor by transpiration. Some groundwater finds openings in the land surface and
emerges as freshwater springs. In river valleys and floodplains, there is often continuous water
exchange between surface water and ground water in the hyporheic zone. Over time, the water returns
to the ocean, to continue the water cycle.

The ocean plays a key role in the water cycle.
The ocean holds "97% of the total water on the planet;
78% of global precipitation occurs over the ocean, and it is the source of 86% of global evaporation".

Important physical processes within the water cycle include the following (in alphabetical order):

Advection: The movement of water through the atmosphere.Without advection, water that evaporated over the oceans
could not precipitate over land.

Atmospheric rivers that move large volumes of water vapor over long distances are an example of advection.

Condensation: The transformation of water vapor to liquid water droplets in the air, creating clouds and fog.

Evaporation: The transformation of water from liquid to gas phases as it moves from the ground or bodies of
water into the overlying atmosphere. The source of energy for evaporation is primarily solar radiation.

Evaporation often implicitly includes transpiration from plants,
though together they are specifically referred to as evapotranspiration.
Total annual evapotranspiration amounts to approximately 505,000 km3 (121,000 cu mi) of water, 434,000 km3
(104,000 cu mi) of which evaporates from the oceans.[7] 86% of global evaporation occurs over the ocean.

Infiltration: The flow of water from the ground surface into the ground. Once infiltrated,
the water becomes soil moisture or groundwater.[9] A recent global study using water stable isotopes,
however, shows that not all soil moisture is equally available for groundwater recharge or for plant
transpiration.

Percolation: Water flows vertically through the soil and rocks under the influence of gravity.

Precipitation: Condensed water vapor that falls to the Earth's surface.

Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet.
Approximately 505,000 km3 (121,000 cu mi) of water falls as precipitation each year, 398,000 km3
(95,000 cu mi) of it over the oceans.[7][12] The rain on land contains 107,000 km3 (26,000 cu mi)
of water per year and a snowing only 1,000 km3 (240 cu mi).[12] 78% of global precipitation occurs
over the ocean.

Runoff: The variety of ways by which water moves across the land.
This includes both surface runoff and channel runoff. As it flows, the water may seep into the ground,
evaporate into the air, become stored in lakes or reservoirs, or be extracted for
agricultural or other human uses.

Subsurface flow: The flow of water underground, in the vadose zone and aquifers.
Subsurface water may return to the surface (e.g. as a spring or by being pumped) or
eventually seep into the oceans. Water returns to the land surface at lower elevation than where it
infiltrated, under the force of gravity or gravity induced pressures. Groundwater tends to move slowly
and is replenished slowly, so it can remain in aquifers for thousands of years.

Transpiration: The release of water vapor from plants and soil into the air.


Residence times

The residence time of a reservoir within the hydrologic cycle is the average time a
water molecule will spend in that reservoir (see adjacent table). It is a measure of
the average age of the water in that reservoir.

Groundwater can spend over 10,000 years beneath Earth's surface before leaving. Particularly
old groundwater is called fossil water. Water stored in the soil remains there very briefly,
because it is spread thinly across the Earth, and is readily lost by evaporation, transpiration,
stream flow, or groundwater recharge. After evaporating, the residence time in the atmosphere is about
9 days before condensing and falling to the Earth as precipitation.

The major ice sheets – Antarctica and Greenland – store ice for very long periods.
Ice from Antarctica has been reliably dated to 800,000 years before present, though the
average residence time is shorter.[14]

In hydrology, residence times can be estimated in two ways.[citation needed] The more
common method relies on the principle of conservation of mass (water balance) and assumes the
amount of water in a given reservoir is roughly constant. With this method, residence times are
estimated by dividing the volume of the reservoir by the rate by which water either enters or
exits the reservoir. Conceptually, this is equivalent to timing how long it would take the reservoir
to become filled from empty if no water were to leave (or how long it would take the reservoir to
empty from full if no water were to enter).

An alternative method to estimate residence times, which is gaining in popularity for dating groundwater,
is the use of isotopic techniques. This is done in the subfield of isotope hydrology.

Water cycle intensification due to climate change

Since the middle of the 20th century, human-caused climate change has resulted in observable
changes in the global water cycle.[19]: 85  The IPCC Sixth Assessment Report in 2021
predicted that these changes will continue to grow significantly at the global and regional level.
These findings are a continuation of scientific consensus expressed in the IPCC Fifth Assessment Report
from 2007 and other special reports by the Intergovernmental Panel on Climate Change
which had already stated that the water cycle will continue to intensify throughout the 21st century.

The effects of climate change on the water cycle are profound and have been described as an
intensification or a strengthening of the water cycle (also called hydrologic cycle).
This effect has been observed since at least 1980.[21]: 1079  One example is the intensification of
heavy precipitation events. This has important negative effects on the availability of freshwater
resources, as well as other water reservoirs such as oceans, ice sheets, atmosphere and land surface.
The water cycle is essential to life on Earth and plays a large role in the global climate and the ocean
circulation. The warming of our planet is expected to cause changes in the water cycle for various reasons.
For example, warmer atmosphere can contain more water vapor which has effects on evaporation and rainfall.

The underlying cause of the intensifying water cycle is the increased amount of greenhouse gases,
which lead to a warmer atmosphere through the greenhouse effect.[22] Physics dictates that saturation
vapor pressure increases by 7% when temperature rises by 1 °C (as described in the Clausius-Clapeyron
equation).

The strength of the water cycle and its changes over time are of
considerable interest, especially as the climate changes. The essence of the overall hydrological
cycle is the evaporation of moisture in one place and the precipitation in other places. In particular,
evaporation exceeds precipitation over the oceans, which allows moisture to be transported by the atmosphere
from the oceans onto land where precipitation exceeds evapotranspiration, and the runoff flows into streams
and rivers and discharges into the ocean, completing the cycle.[24] The water cycle is a key part of
Earth's energy cycle through the evaporative cooling at the surface which provides latent heat to the
atmosphere, as atmospheric systems play a primary role in moving heat upward.

General nature of the cycle

The present-day water cycle at Earth’s surface is made up of several parts.
Some 496,000 cubic km (about 119,000 cubic miles) of water evaporates from the land
and ocean surface annually, remaining for about 10 days in the atmosphere before falling
as rain or snow. The amount of solar radiation necessary to evaporate this water
is half of the total solar radiation received at Earth’s surface. About one-third of the
precipitation falling on land runs off to the oceans primarily in rivers, while direct
groundwater discharge to the oceans accounts for only about 0.6 percent of the total discharge.
A small amount of precipitation is temporarily stored in the waters of rivers and lakes.
The remaining precipitation over land, 73,000 cubic km (17,500 cubic miles) per year, returns
to the atmosphere by evaporation. Over the oceans, evaporation exceeds precipitation, and the net
difference represents transport of water vapour over land, where it precipitates as rain or snow
and returns to the oceans as river runoff and direct groundwater discharge.

The various reservoirs in the water cycle have different water residence times.
Residence time is defined as the amount of water in a reservoir divided by either the rate
f addition of water to the reservoir or the rate of loss from it. The oceans have a water
residence time of 3,000 to 3,230 years; this long residence time reflects the large amount of
water in the oceans. In the atmosphere the residence time of water vapour relative to total
evaporation is only about 10 days. Lakes, rivers, ice, and groundwaters have residence times
lying between these two extremes and are highly variable.

There is considerable variation in evaporation and precipitation over the globe.
In order for precipitation to occur, there must be sufficient atmospheric water
vapour and enough rising air to carry the vapour to an altitude where it can condense
and precipitate. Precipitation and evaporation vary with latitude and their relation
to the global wind belts. The trade winds, for example, are initially cool,
but they warm up as they blow toward the Equator. These winds pick up moisture
from the ocean, increasing ocean surface salinity and causing seawater at the surface to sink.
When the trade winds reach the Equator, they rise, and the water vapour in them condenses and forms clouds.
Net precipitation is high near the Equator and also in the belts of the prevailing westerlies, where there is
frequent storm activity. Evaporation exceeds precipitation in the subtropics, where the air is stable,
and near the poles, where the air is both stable and has a low water vapour content because of the cold.
The Greenland Ice Sheet and the Antarctic Ice Sheet formed because the very low evaporation rates at the
poles resulted in precipitation exceeding evaporation in these local regions.

Water vapour and precipitation
As noted above, water exists in the atmosphere in gaseous form. Its liquid form,
either as water droplets in clouds or as rain, and its solid form, as ice crystals in clouds,
snowflakes, or hail, occur only momentarily and locally.

Water vapour performs two major functions: (1) it is important to the radiation balance of
Earth, as its presence keeps the planetary surface warmer than would otherwise be the case,
and (2) it is the principal phase of the ascending part of the water cycle.

The mass of water vapour in the atmosphere, which represents only 0.001 percent of the
hydrosphere, is highest in the tropics and decreases toward the poles. At a mean temperature
of Earth’s surface of 15 °C (59 °F), the partial pressure of water vapour at equilibrium with
pure water is 0.017 atmosphere. The addition of salts to pure water lowers its vapour pressure.
The equilibrium, or saturation, water vapour pressure of a saturated solution of sodium chloride
is 22 percent lower than that of pure water. Precipitable water vapour has, on the average,

a vapour pressure of 0.0025 atmosphere, which amounts to 15 percent of the saturation vapour
pressure. The ratio of observed water vapour pressure to the saturation vapour pressure at
the same temperature is the relative humidity of the air. Thus, the mean relative humidity
of the atmosphere is only 15 percent, a value that is low in human terms, in which
levels of 50 to 60 percent are preferred for maximum comfort. The relative humidity
of the air, however, varies greatly from one geographic region to another and also

vertically in the atmosphere. Atmospheric water vapour decreases rapidly with increasing
altitude relative to its surface value. The amount of water required to saturate a volume
of air depends on the temperature of the air. Air at high temperature can hold more water
vapour at saturation than can air at low temperature. Because the temperature of the lower
atmosphere (the troposphere) decreases rapidly with increasing altitude to about 15 km (about 9 miles),
the upper levels of the troposphere contain little water vapour; most of the vapour is
found within a few kilometres of Earth’s surface. The average relative humidity of tropospheric
air is about 50 percent. Above 15 km, water vapour is essentially frozen out of the atmosphere,
amounting to less than 0.1 percent of its concentration at Earth’s surface.

Aside from temperature, other factors determine the water vapour content of the air and
are particularly important in the lower troposphere. These factors include local evaporation
and the horizontal atmospheric transportation of moisture, which varies with altitude, latitude,
season, and topography. During a period of 10 days (i.e., the residence time of water in the atmosphere),
horizontal eddy turbulence may disperse vapour over distances up to 1,000 km (600 miles).

When a mass of air at Earth’s surface is exposed to a body of water, it gains water by evaporation or
loses water by precipitation, depending on its relative humidity. If the air is undersaturated, with a
relative humidity of less than 100 percent, it gains water vapour because the rate of
evaporation exceeds the rate of condensation. If the air is supersaturated, with a relative
humidity greater than 100 percent, the air mass loses water vapour because the rate of precipitation
exceeds that of evaporation. This interaction between air masses and surface water bodies drives the
atmosphere toward a state of saturation, which is not achieved for the entire atmosphere because of
the variability in weather and because not all air masses are in contact with water bodies. In general,
the level of atmospheric water vapour is higher in the summer, since temperatures are higher at this
time of year. Also, atmospheric water vapour content is higher near the source of moisture than in
distant regions. Over the oceans, the air is almost always near saturation, whereas over the deserts,
where the supply of moisture is limited, the air is far below water vapour saturation values. In most
cases, atmospheric water vapour content decreases inland over continents, but this decrease
is modified by rainfall conditions, by the presence or absence of high mountains, large lakes, extensive
forests, and swamps, and by the prevailing wind directions. Horizontal winds and air mass movements
transfer water vapour from the ocean to the land. Although the processes are not completely separable,
the horizontal transfer of water vapour seldom causes the vapour to undergo condensation, whereas vertical
movements are most important in the condensation process.

Condensation depends strongly on the average temperature of Earth’s surface because the water
vapour content of the air is strongly dependent on temperature. In figures that show the states of
water as a function of the variables of pressure and temperature, the slope of the phase boundary
between liquid water and water vapour is positive, implying that with increasing temperature the
air at equilibrium will hold increasing amounts of water vapour. Cooling or mixing of this air
results in condensation of the vapour and precipitation as water droplets or as ice crystals if
the air temperature is below 0 °C (32 °F). When first formed, the water droplets or ice crystals
are very small, on the order of 10−2 to 10−3 cm (0.004 to 0.0004 inch) in diameter, and they
float freely in the atmosphere. In large quantities, these water droplets and ice crystals
produce a cloud. All clouds are formed as a result of cooling below the dew point,
the temperature at which condensation begins when air is cooled at constant pressure and constant
water vapour content. When the droplets or crystals coalesce to a size of about 10−2 cm (0.004 inch)
in diameter, they become heavy enough to fall as raindrops or snowflakes. Hailstones measure about
10−1 cm (0.04 inch) in diameter or much larger. Water vapour condensing in the atmosphere contains
strongly soluble salts (mostly of oceanic origin), weakly soluble or insoluble solids (dust),
and dissolved gases. The dust and sea salt aerosol particles in the air may act as sites of
condensation by serving as nuclei for bringing initially a few water molecules together and inducing condensation from supersaturated air.

Distribution of precipitation
Precipitation falling toward Earth’s surface may suffer several fates. It may be evaporated
during its fall or after it reaches the ground surface. If the surface is covered with dense
vegetation, much of the precipitation may be held on leaves and plant limbs and stems. This
process is termed interception and may result in little water reaching the ground because
the water may be directly evaporated from plant surfaces back into the atmosphere. If
precipitation reaches the ground in the form of snow, it may remain there for some time.
On the other hand, if precipitation falls as rain, it may evaporate, infiltrate the soil,
be detained in small catchment areas, or become overland flow—a form of runoff. Overland
flow (Ro) may be expressed in terms of intensity units, water depth per unit of time (e.g.,
centimetres per hour, or inches per hour), as Chemical equation.

where P is precipitation rate and I is infiltration rate (rate of entry and downward movement
of water into the soil profile). Infiltration rate will equal precipitation rate until the
limit of the infiltration rate, or infiltration capacity, is reached. Soil infiltration rates
are usually high at the beginning of a rain preceded by a dry spell and decrease as the rainfall
continues. This change in rate is due to the clogging of soil pores by particles brought from
above by the infiltrating rain and to the swelling of colloidal soil particles as they absorb
water. Thus, rapid decreases in infiltration rates during a rain are more likely to occur in
clay-rich soils than in sandy soils.

Between rainfall periods, water held in the soil as moisture is gradually lost by direct
evaporation or by withdrawal by plants. Evaporation into the open atmosphere occurs at the
surface of the soil, and the soil dries progressively downward with time. Water vapour in
the soil diffuses upward, replenishing the evaporated water, and in turn is evaporated.
The pumping of air into and out of the soil by atmospheric pressure changes enhances the
movement of soil moisture upward. It has been shown that evaporation of a water droplet
in the free atmosphere, and to a first approximation in various soil atmospheres, is
proportional to the droplet surface area 4πr2 (square centimetres, where r is the radius
of the droplet), the diffusional flux of water at the droplet surface, and the transfer
of heat as the droplet evaporates. The equation for the rate of shrinkage of a water
droplet due to evaporation is Chemical equation.

where dr/dt is the rate of change in the radius of the water droplet (centimetres per second),
D is the diffusion coefficient of water vapour in air (cubic centimetres per second), ρvo is
the equilibrium vapour concentration at the droplet surface, Sp is the degree of undersaturation
of water vapour in the environment, ρL is the density of liquid water (grams per cubic centimetre),
and X is a dimensionless parameter depending on D, ρvo, temperature, the heat of evaporation of
water vapour, the coefficient of thermal conductivity of air, and the spherical coordinate system
necessary to define processes occurring to a spherical water droplet. Water droplets
shrink—dr/dt < 0, evaporate—when the water vapour concentration in the environment
(atmosphere or soil atmosphere) is less than the saturation water vapour concentration
at the droplet surface. They grow—dr/dt > 0, condense—when the converse is true in the
free atmosphere. The term dr/dt has negative values for evaporation and positive ones
for condensation. Use of this equation shows, as an example, that it would take 23 minutes
for a water droplet to shrink (evaporate) in size from 50 to 5 micrometres (0.002 to 0.0002 inch)
in air at 10 °C (50 °F) and a water vapour undersaturation of 1 percent.

Besides simple evaporation of water from soils, water is also returned to the atmosphere by
transpiration in plants. Plants draw water from soil moisture through their vast network of
root hairs and rootlets. This water is carried upward through the plant trunk and branches
into the leaves, where it is discharged as water vapour. The term evapotranspiration is used
in climatic and hydrologic studies to include the combined water loss from Earth’s surface
resulting from evaporation and transpiration. The maximum possible evapotranspiration is
termed potential evapotranspiration and is governed by the available heat energy. It is
taken as equal to evaporation from a large water surface and is generally much less than
actual evapotranspiration. Actual evapotranspiration is never greater than precipitation
except on irrigated land because of percolation of water into groundwater bodies and surface runoff.

The soil moisture zone gains water by precipitation and infiltration and loses water by
evapotranspiration, overland flow, and percolation of water downward due to gravity
into the groundwater zone. The contact between the groundwater zone (phreatic zone) and
the overlying unsaturated zone (vadose zone) is called the groundwater table. The water
balance equation for change of moisture storage in a soil is given as Chemical equation.

where S is storage, P is precipitation, E is evaporation, and R is surface runoff plus
percolation rate into the groundwater zone; all terms are in units of length per unit
of time (e.g., millimetres per day, centimetres per month). In humid midlatitude climates
where a strong contrast between winter and summer temperatures exists, there is an annual
cycle of the water content of soils. The annual cycle of moisture in soil in Ohio, U.S.,
for example, demonstrates the processes controlling soil moisture. Of special importance is
the fact that the soils are saturated in this temperate climate in the spring, and the
evaporation rate is low because of the low input of radiant energy from the Sun. By contrast,
in the summer, evaporation increases because of increasing solar radiation, and with the growth
of plants so does transpiration. Soil moisture is reduced to very low levels at this time of year.

Groundwaters and river runoff

The term R in the water balance equation for change of soil moisture storage above represents
groundwater and river runoff losses from the soil moisture zone. Water percolates from the soil
moisture zone through the unsaturated (vadose) zone to the water table. Flow through the
unsaturated zone is complicated. After a rainfall, water may form a nearly continuous phase
in pores in this zone, but, with drying, the last amount of water is held in clusters at points
of contact of solid grains and as thin films on solid surfaces. The flow paths of water become
more tortuous, and the water-conducting properties decrease rapidly. Structured soils and fractured
rock in the vadose zone may act as conduits for fluids to reach the water table. Because of the complex
geometry of water contained in the unsaturated zone, the properties of water are expressed by means of
empirical relationships. Darcy’s law, derived in 1856 from experimentation by the French engineer Henri
Darcy, permits quantification of water flow through porous media. The law states that the rate of
flow Q of a fluid through a porous layer of medium (e.g., a sand bed) is directly proportional to the
area A of the layer and to the difference Δh between the fluid heads at the inlet and outlet faces of
the layer and is inversely proportional to the thickness L of the layer. Expressed analytically, Chemical equation.

where K is a constant characteristic of the medium.
The term K for a porous rock medium is the volume of fluid of unit viscosity passing
through a unit cross section of the rock in unit time under the action of a unit pressure
gradient; this characteristic is called permeability. The permeability of a rock is
dependent on the geometric properties of the rock, such as porosity, shape and size
distribution of constituent rock grains, and degree of cementation of the rock.
Permeabilities of rocks vary greatly. Unconsolidated sands may have permeabilities
measured in hundreds of darcys, whereas consolidated sands that will transmit reasonable
amounts of fluid have permeabilities of 0.01 to 1 darcy. A rough idea of the meaning of
one darcy of permeability (which equals 9.869 × 10−12 square metre [1.261 × 10−11 square foot])
can be obtained by imagining a cube of sand one foot on a side. If the sand has a permeability
of one darcy, approximately one barrel of water per day will pass through the one-foot cube with
a one-pound pressure head. The general equation of Darcy can be modified to express flow in both
the unsaturated zone and the saturated groundwater zone.

Groundwater is constantly in motion. When a lake or stream intersects the groundwater table,
groundwater communicates directly with these bodies of water. If the groundwater table is higher
than the stream or lake level, a pressure head will develop such that the groundwater flows
into the water body; conversely, if the groundwater table is lower than the river or lake level,
the pressure gradient induces flow into the groundwater. Most groundwater ultimately reaches the
channels of surface streams and rivers and flows to the sea. On the average, groundwater contributes
to total river runoff about 30 percent of its water on a global basis.

Water runoff from the land surface is that part of precipitation which eventually appears in
perennial or intermittent surface streams. Streamflow-generation mechanisms have been studied
for several decades, and there is now considerable knowledge regarding rainfall runoff processes
and their controls. This understanding is the result of both careful observations from field
experiments and the heuristic simulations of hypothetical realities with rigorous mathematical models.
The discharge measured at the downstream end of a channel reach is supplied by channel inflow at the
upstream end of the reach and by the lateral inflows that enter the channel from the hillslope along
the reach. The lateral inflows may arrive at the stream in one of three forms: (1) groundwater flow,
(2) subsurface storm flow, or (3) overland flow.

Groundwater flow provides the base flow component of streams that sustains their flow between
storms. The “flashy” response of streamflow to individual precipitation events may be ascribed
to either subsurface storm flow or overland flow. Under intense rainfall events during which
the surface soil layer becomes saturated to some depth, water is able to migrate through “preferred pathways”
rapidly enough to deliver contributions to the stream during the peak runoff period. The conditions for
subsurface storm flow are quite restrictive. The mechanism is most likely to be operative on steep, humid,
forested hillslopes with very permeable surface soils.

Overland flow is generated at a point on a hillslope only after surface ponding takes place.
Ponding cannot occur until the surface soil layers become saturated. It is now widely recognized
that surface saturation can occur because of two quite distinct mechanisms—specifically, Horton overland
flow (named for American hydraulic engineer and hydrologist Robert E. Horton) and Dunne overland flow
(named for British hydrologist Thomas Dunne).

The former classic mechanism is for a precipitation rate that exceeds the saturated hydraulic
conductivity of the surface soil. A moisture content versus depth profile during such a rainfall
event will show moisture contents that increase at the surface as a function of time. At some point
in time the surface becomes saturated, and an inverted zone of saturation begins to propagate downward
into the soil. It is at this time that the infiltration rate drops below the rainfall rate and overland
flow is generated. The time is called the ponding time. The necessary conditions for the generation of
overland flow by the Horton mechanism are (1) a rainfall rate greater than the saturated hydraulic
conductivity of the soil and (2) a rainfall duration longer than the required ponding time for a given
initial moisture profile. Horton overland flow is generated from partial areas of the hillslope where
surface hydraulic conductivities are lowest.

In Dunne overland flow, the precipitation rate is less than the saturated hydraulic conductivity,
and the initial water table is shallow or there is a shallow impeding layer. Surface saturation occurs
because of a rising water table; ponding and overland flow occur at a time when no further soil moisture
storage is available. The Dunne mechanism is more common to near-channel areas. Dunne overland flow is
generated from partial areas of the hillslope where water tables are shallowest. Both Horton and Dunne
mechanisms result in variable source areas that expand and contract through wet and dry periods.

Total river discharge and the chemistry of the discharge vary from continent to continent; some
continents are wetter and some drier than the world average, but the deviations are not extreme.
The runoff per unit area from Asia and Europe is almost exactly equal to the world average; it is a
little lower in Africa and North America; and it is considerably higher in South America. Antarctica
is frozen and Australia is arid, and so they contribute little runoff. Also, since their areas are
relatively small, they do not affect the global runoff average significantly. The waters draining
the continents have quite different chemistries; those from Europe are very rich in calcium and
bicarbonates, whereas those from Africa and South America are not. North American and Asian rivers
re somewhat intermediate in their concentrations of these dissolved constituents. Such differences
in composition reflect a variety of factors, including runoff, temperature, and relief, but certainly
the bulk composition of the continental rocks in contact with these waters and their underground sources
play a major role. The surface rocks of Europe are rich in carbonates, and those of South America are not;
the latter are dominated by sediments rich in silicate minerals.

The chemistry of groundwater and river runoff is being modified by human activities on a global
scale. The natural dissolved riverine input of major constituents to the oceans already has been
increased by more than 10 percent because of human activities. In the case of sodium, chlorine,
and sulfate, the increases are as high as 30 percent. In the United States alone, total water use
is equivalent to one-third of total runoff, with about 2 percent of the water used coming from
underground wells. In the southwestern region of the country, water supplies have been tapped heavily
and in some areas have been exhausted with no hope of replacement. This extensive use of fresh waters in
the United States and throughout the globe makes them particularly susceptible to pollution. Leachates
from fertilizers, herbicides, and pesticides are found in some freshwater bodies; toxins or excessive
amounts of certain inorganic or organic chemicals are present; radioactive elements have been detected;
and some surface water bodies have had their salinities increased dramatically, rendering them useless
for human consumption. It is therefore imperative that countries closely monitor the use of freshwater
systems and promote their conservation.

The EPI - Environmental Performance Index EPI provides a data-driven
summary of the state of sustainability around the world. Using 40 performance
indicators across 11 issue categories, the EPI ranks 180 countries on climate
change performance, environmental health, and ecosystem vitality.
These indicators provide a gauge at a national scale of how close countries
are to established environmental policy targets. The EPI offers a
scorecard that highlights leaders and laggards in environmental
performance and provides practical guidance for countries that aspire
to move toward a sustainable future.

EPI indicators provide a way to spot problems, set targets, track trends,
understand outcomes, and identify best policy practices. Good data and
fact-based analysis can also help government officials refine their policy
agendas, facilitate communications with key stakeholders, and maximize the
return on environmental investments. The EPI offers a powerful policy
tool in support of efforts to meet the targets of the UN Sustainable
Development Goals and to move society toward a sustainable future.

Overall EPI rankings indicate which countries are best addressing the
environmental challenges that every nation faces. Going beyond the
aggregate scores and drilling down into the data to analyze performance
by issue category, policy objective, peer group, and country offers even
greater value for policymakers. This granular view and comparative
perspective can assist in understanding the determinants of environmental
progress and in refining policy choices.

Over 2 billion people — nearly 25% of the world’s population — currently
drink unsafe water, and nearly 3.6 billion
people lack access to basic sanitation services like sewage treatment.
Without clean water, morbidity and
mortality remain high in many regions of the globe, particularly Sub-Saharan
Africa and Southern Asia.

The world has made only modest progress in reducing poor health
outcomes from inadequate Sanitation & Drinking Water.
Countries striving to improve their water and sanitation
infrastructure under Sustainable Development Goal 6 often lack
the financial or engineering capacity to adequately achieve healthy standards,
illustrating the importance of international aid in the form of funding and
technology sharing. Global and national leaders must
take considerable action to expand safe drinking water
and sanitation access to the billions of people who suffer
from the lack of these services.

Ensuring universal access to safely managed sanitation
and drinking water promotes human health and sustainable development. Clean water and proper sanitation are
essential to preventing the transmission of disease
(Prüss-Üstün et al., 2008), including the COVID-19 virus
(Otto et al., 2020). Despite the importance of safe water
maintaining an individual's well-being, 2 billion people lack
access to clean drinking water and 3.6 billion people lack
basic sanitation services (UN-Water, 2021).

As climate change warms the world, ecosystems that
provide water shrink, making water access more unpredictable and scarce (UN-Water, 2021). These trends
exacerbate gender inequalities in societies, as the burden
of fetching clean water from far-away sources often falls
on women (Kayser et al., 2019). The 2022 EPI Sanitation &
Drinking Water metrics track diseases and deaths from
exposure to unsafe sanitation and drinking water, providing countries with insights on whether their water
infrastructure is sufficient to maintain public health

Unsafe Sanitation (40% of issue category)
We measure unsafe sanitation using the number of age-standardized disability-adjusted life-years lost per 100,000 persons (DALY rate) due to their exposure to
inadequate sanitation facilities.
Unsafe Drinking Water (60% of issue category)
We measure unsafe drinking water using the number of age-standardized disability adjusted life-years lost per 100,000 persons (DALY rate) due to exposure to unsafe
drinking water.

The world remains far from establishing universal access
to safely managed drinking water and sanitation services.
Between 2000 and 2020, however, 2 billion individuals
gained access to clean water and 2.4 billion individuals
gained improved sanitation services (WHO and UNICEF,
2021). Figure 6-2 shows that the number of lives lost due
to unsafe water or inadequate sanitation has steadily decreased for the last thirty years.
Sustainable Development Goal 6 outlines a target of ensuring available and safely managed water for all by 2030
(Sadoff et al., 2020). While this ambitious target highlights the importance of clean water, reaching it will not
be easy. Achieving universal access to both safely managed drinking water and sanitation services in this
timeline will require a four-fold increase in current levels
of progress (UN-Water, 2021). Without substantial investment, an estimated 1.6 billion people will lack access
to safe drinking water at home and 2.8 billion people will
lack safe sanitation services by 2030 (WHO and UNICEF,
2021).

Geographic inequities in access to safe drinking water
and sanitation exist in many regions (Prüss-Üstün et al.,
2008). While, on average, 74% of the global population
drinks safe water, access ranges widely from 96% in Europe and North America to just 54% in Sub-Saharan
Africa (UN-Water, 2021; WHO and UNICEF, 2021). Poor
countries house the majority of individuals who face unsafe conditions — over 50% of those who lack access to
safe drinking water and 40% of those who lack basic sanitation services live in the least developed countries (UNWater, 2021). Water insecurity is particularly threatening
to rural communities, who often lack improved drinking
water and sanitation infrastructure. In urban areas, population growth has outpaced progress, meaning there are
more people currently without at least a basic water and
sanitation service than there were in 2000 (UNICEF,
2020).

Wealthy countries in the Global West lead the world in
the Sanitation & Drinking Water issue category, with minimal deaths related to exposure to unsafe sanitation and
unsafe drinking water. Several of the top-performing
countries are in the European Union, highlighting these
countries' continued commitment to policies that promote safely managing water and sanitation. In December
2020, the European Union updated the Drinking Water
Directive to confront emerging pollutants, like microplastics, and to increase information accessibility for citizens
(European Commission, 2020).

Several small island developing countries land in the middle of Sanitation & Drinking Water rankings. Nearly 70%
of small island developing states face water scarcity,
slowing progress to provide safe water for residents. In
addition, climate change consequences, including sea
level rise, variable rainfall, and increased frequency of severe weather events, are exacerbating water shortages
(UNCTAD, 2021). Singapore, however, stands out as a
leader among these countries. While the country experiences heavy rainfall, its small surface area prevents the
nation from establishing water storage units and aquifers.
Singapore has recently expanded infrastructure like rainwater catchment systems and recycling processes to
supplement imports from Malaysia and adequately supply water (UNCTAD, 2021). Nationally set water prices
and education programs further encourage residents not
to waste water (UNCTAD, 2021).

Despite being the largest economy in Southeast Asia, Indonesia still faces risks from unsafe sanitation practices
and drinking water. Almost 25 million people in Indonesia
lack access to toilets or latrines, leading to contaminated
water supplies and the spread of diarrheal diseases
(UNICEF, 2022). In West Java, fecal matter and heavy
metals pollute the Citarum River, which millions of Indonesians rely on for water and food (Price and Price, 2017).
Responding to pressure from international organizations,
the Indonesian government has established a cleaning
program with the intent to make the river’s water drinkable by 2025. The decentralized framework and poor
enforcement of Indonesia’s environmental regulations,
however, presents challenges on the road to improvement (Holzhacker et al., 2016).

Many Sub-Saharan African countries receive low rankings
in Sanitation & Drinking Water. In 2020, half of the individuals who lacked access to basic drinking water lived in
this region (WHO and UNICEF, 2021). Geographic inequalities also exist at the sub-national level. Safe drinking
water access ranges from upwards of 50% in urban areas to just 13% in rural areas (WHO and UNICEF, 2021). In recent years, many countries in Sub-Saharan Africa have
increased access to improved wells and springs, but access to piped water — a more reliable source — remains
uncommon (Deshpande et al., 2020). Insufficient infrastructure, as well as a disproportionate distribution of
water storage units, fuels these disparities. In addition,
transboundary water laws have contributed to conflict
over water in sub-Saharan Africa. For example, the 1959
Nile Basin agreement established Sudan and Egypt as the
only actors with power over the allocation of Nile resources, despite the vested interests of several other
nearby countries (Tatlock, 2006). To ensure broader access to water resources, the region should seek
multilateral input on how to sustainably manage the Nile.

Unsafe sanitation and unsafe drinking water use the
GBD’s Comprehensive Risk Assessment (CRA) framework
to estimate the impacts of exposure to unsafe sanitation
and drinking water, measured by Disability-Adjusted Life
Years (DALYs) lost per 100,000 persons (Kyu et al., 2018).
This provides a standard metric for comparing performance across countries. The metrics first examine the
estimated exposure to health risks in each country. For
these indicators, the minimum level of exposure to unsafe
drinking water is defined as “All households have access
to water from a piped water supply that is also boiled or
filtered before drinking,” and for unsafe sanitation, minimum exposure means “All households have access to
toilets with sewer connection” (Forouzanfar et al., 2016). The second step uses statistical models to estimate the
portion of deaths and DALYs lost attributable to those
risks.

It remains difficult to track all adverse health outcomes
from the lack of safe drinking water and sanitation. The
GBD evaluates three key measures: diarrheal diseases, typhoid fever, and paratyphoid fever. Data on the health
risks and outcomes from diarrheal disease are much
stronger than the studies on typhoid and paratyphoid,
stemming from gaps in the literature and on-the-ground
data on the prevalence of these illnesses.

Unsafe sanitation and unsafe drinking water currently
only track adverse health outcomes from exposure to biological risks, such as bacteria. Risks of illness or death
from chemical contaminants, like lead and pesticides, are
not considered. Despite their exclusion here, exposure to
chemical pollutants poses serious health concerns in
both the developed and developing world.

Water quality assessments also rest on the assumption
that “improved” water supplies are safe, but a significant
number of water sources that meet the definition of an
“improved” source still do not meet WHO guidelines
(Clasen et al., 2014). Even piped water sources and groundwater from wells (as opposed to open water) may be
contaminated by soil pollutants or nearby latrine pits
(Back et al., 2018). Infrastructure is not always indicative
of health outcomes.

EPI Framework
The framework organizes 40 indicators into 11 issue categories and three policy objectives,
with weights shown at each level as a percentage of the total score.

rankink contries Environmental Performance Index - EPI Framework
country;rank;epi score;10-year change
Finland;1;100.00;0.60
Iceland;2;100.00;1.10
Netherlands;3;100.00;NA
Norway;4;100.00;0.90
Switzerland;5;100.00;NA
United Kingdom;6;100.00;1.00
Malta;7;99.80;1.70
Germany;8;99.10;0.90
Luxembourg;9;98.70;2.20
Sweden;10;98.60;1.80
Italy;11;98.30;1.60
Greece;12;98.20;0.80
Denmark;13;97.50;2.50
Ireland;14;97.40;1.90
Spain;15;96.90;1.10
France;16;96.30;4.80
Japan;17;95.10;1.00
Austria;18;94.70;1.00
Cyprus;19;94.00;1.60
Belgium;20;93.60;3.80
Singapore;21;93.30;0.70
Israel;22;92.90;2.20
South Korea;23;90.80;2.40
Canada;24;88.10;2.90
Australia;25;87.10;1.70
United States of America;26;86.10;2.30
Brunei Darussalam;27;85.70;1.60
Portugal;28;83.50;3.00
New Zealand;29;80.40;2.00
Czech Republic;30;76.50;0.40
Slovenia;31;74.70;0.60
Taiwan;32;72.40;2.30
Slovakia;33;71.90;2.20
Poland;34;71.80;2.50
Uruguay;35;70.80;5.90
Croatia;36;70.30;2.20
Bulgaria;37;68.40;3.30
Chile;38;68.10;3.60
Kuwait;39;67.50;2.70
United Arab Emirates;40;67.20;1.90
Qatar;41;66.60;3.30
Costa Rica;42;66.20;4.10
Montenegro;43;65.60;3.40
Serbia;43;65.60;3.30
Mauritius;45;65.50;3.90
Argentina;46;64.80;4.40
Jordan;47;62.70;8.40
Hungary;48;62.20;0.70
Estonia;49;61.90;1.30
Bosnia and Herzegovina;50;61.50;3.90
North Macedonia;51;61.10;2.90
Belarus;52;60.50;1.70
Lebanon;53;59.80;5.90
China;54;59.50;6.00
Saudi Arabia;55;59.30;6.80
Latvia;56;59.10;1.50
Lithuania;57;58.40;1.20
Oman;58;58.30;3.70
Malaysia;59;57.60;2.70
Armenia;60;57.30;1.50
Bahrain;61;56.60;2.50
Romania;62;56.00;3.30
Colombia;63;55.90;6.80
Thailand;63;55.90;5.20
Russia;65;55.50;1.30
Kazakhstan;66;55.20;4.20
Ukraine;66;55.20;-0.50
Bahamas;68;55.00;0.70
Albania;69;54.10;2.80
Iran;70;53.70;4.40
Trinidad and Tobago;71;53.40;1.80
Algeria;72;53.30;3.90
Mexico;73;52.90;4.90
Viet Nam;74;52.80;4.40
Turkey;75;52.70;4.50
Tunisia;76;52.60;1.70
Uzbekistan;77;52.10;2.10
Barbados;78;52.00;0.20
Georgia;79;51.70;2.30
Seychelles;80;51.50;3.00
Ecuador;81;50.30;7.10
Antigua and Barbuda;82;50.10;1.10
Moldova;83;50.00;1.80
Cuba;84;49.70;1.60
Iraq;84;49.70;12.10
Jamaica;86;49.40;0.30
Samoa;87;49.30;1.60
Sri Lanka;88;48.50;5.20
Maldives;89;47.80;4.00
Dominica;90;47.60;0.90
Paraguay;90;47.60;5.70
Turkmenistan;92;47.40;9.10
Grenada;93;47.10;1.00
Venezuela;94;46.80;2.60
Tonga;95;46.50;1.00
Brazil;96;46.20;8.50
Azerbaijan;97;45.60;2.40
Kyrgyzstan;97;45.60;5.60
Saint Lucia;99;45.40;0.80
Panama;100;43.60;7.10
Saint Vincent and the Grenadines;100;43.60;1.80
Mongolia;102;43.20;3.60
Peru;103;43.10;2.20
Nicaragua;104;42.90;7.60
Belize;105;42.70;2.80
El Salvador;106;41.70;4.10
Morocco;107;40.90;10.00
Bolivia;108;40.10;6.50
Suriname;109;39.40;3.70
Dominican Republic;110;39.00;3.50
Philippines;110;39.00;8.00
Egypt;112;36.70;9.30
Cabo Verde;113;35.60;4.90
Micronesia;114;35.50;2.30
Guyana;115;35.30;6.00
Sao Tome and Principe;115;35.30;12.00
Fiji;117;34.70;3.40
Cambodia;118;34.30;8.30
Equatorial Guinea;119;33.20;10.50
Marshall Islands;120;32.30;5.20
Honduras;121;31.80;6.40
Bhutan;122;31.20;5.60
Myanmar;123;30.90;10.50
Tajikistan;123;30.90;6.70
Indonesia;125;28.50;7.70
Guatemala;126;28.30;8.00
Afghanistan;127;28.10;8.30
Gabon;128;27.70;9.80
Bangladesh;129;27.40;5.70
Nepal;130;27.10;8.90
Laos;131;26.60;9.90
Timor-Leste;132;26.00;4.40
South Africa;133;24.70;7.80
Sudan;134;22.40;11.10
Vanuatu;135;21.50;3.30
Botswana;136;20.90;6.50
Ghana;136;20.90;4.30
Namibia;138;19.70;5.60
India;139;19.50;9.60
Gambia;140;19.20;5.70
Tanzania;141;18.50;5.80
Djibouti;142;18.30;5.10
Uganda;143;17.60;3.40
Pakistan;144;17.50;5.70
Cote d'Ivoire;145;17.30;6.10
Rwanda;146;16.90;6.90
Zimbabwe;146;16.90;8.50
Mozambique;148;16.40;6.40
Kiribati;149;16.30;4.20
Papua New Guinea;150;15.60;4.00
Comoros;151;15.20;5.60
Republic of Congo;152;14.60;10.10
Haiti;153;14.10;3.30
Solomon Islands;153;14.10;4.80
Kenya;155;13.70;6.80
Dem. Rep. Congo;156;13.60;10.30
Mauritania;156;13.60;8.50
Benin;158;13.50;4.60
Zambia;158;13.50;7.60
Senegal;160;13.10;4.30
Angola;161;12.80;9.50
Eswatini;162;12.60;6.10
Malawi;163;12.10;5.30
Sierra Leone;164;11.60;4.40
Guinea;165;11.30;5.10
Ethiopia;166;11.00;5.80
Liberia;167;9.90;7.50
Mali;168;8.30;5.60
Burkina Faso;169;7.80;3.70
Cameroon;169;7.80;6.50
Lesotho;171;7.30;4.10
Guinea-Bissau;172;6.80;6.80
Eritrea;173;6.40;4.60
Madagascar;174;6.00;5.10
Burundi;175;5.40;2.90
Togo;176;5.20;5.20
Nigeria;177;5.00;5.00
Niger;178;1.50;1.50
Central African Republic;179;NA;NA
Chad;179;NA;NA