# Presentation: 623293

## Pioneers in the study of atmospheric motions
Pioneers in the study of cooling and warming influences on the surface
Early attempts at forecasting and modeling
How orbital mechanics explains long-term climate changes
Scientists prove CO2 is rising, humans are the cause
A timeline of aerial photography and photogrammetry
The stratospheric ozone scare & call for global assessments
NASA’s Earth Science Enterprise & Earth Observing System
Brief review on why satellite remote sensing is useful
References & recommended further reading

**Pioneers in the study of cooling and warming influences on the surface**
**Early attempts at forecasting and modeling**
**How orbital mechanics explains long-term climate changes**
**Scientists prove CO****2**** is rising, humans are the cause**
**A timeline of aerial photography and photogrammetry**
**The stratospheric ozone scare & call for global assessments**
**NASA’s Earth Science Enterprise & Earth Observing System**
**Brief review on why satellite remote sensing is useful**
**References & recommended further reading**

***A Brief History of Earth System Science and Satellite Remote Sensing***

***Presentation Overview***

## Edmond Halley (1656-1742), British astronomer 1
Drew the first documented map of the known trade winds, circa 1686
Although Halley clearly showed the proper trade winds, Halley had trouble describing the physics behind them. Halley used the laws of buoyancy to try to describe the phenomena he witnessed. When air is heated, it rises and as it rises, more air must flow inwards to make up for the void. Halley knew of the rotation of the Earth and surmised that the incoming air had to move from the east to compensate.

**Edmond Halley (1656-1742), British astronomer **1
- Drew the first documented map of the known trade winds, circa 1686
- Although Halley clearly showed the proper trade winds, Halley had trouble describing the physics behind them. Halley used the laws of buoyancy to try to describe the phenomena he witnessed. When air is heated, it rises and as it rises, more air must flow inwards to make up for the void. Halley knew of the rotation of the Earth and surmised that the incoming air had to move from the east to compensate.

## George Hadley (1685-1768), English lawyer & scientist 2
“I think the causes of the General Trade-Winds have not been fully explained by any of those who have wrote on that subject.” (1735)
In 1735, Hadley expounded upon the ideas of Halley.  Instead of simple currents traveling east, he envisioned a Coriolis acceleration that is latitude dependent.  
He also envisioned an "anti-trade" wind that blew to the northeast above the surface southeast trades and found that the mid-latitude westerly got their eastward velocity from sinking dense and fast air from aloft. These ideas still hold valid today.
First to describe tropical circulation in 1753. He envisaged the heat surplus of the equatorial regions driving large-scale circulation cells consisting of air rising in the tropics and then sinking 30 degrees north and south. This sinking air would then flow back towards the equator. His simple idea was to become the basis of the general circulation of the atmosphere as it is understood today.
Both men agreed upon the idea of upper tropospheric meridional circulations. They knew that the equatorial region would have the highest temperature and therefore the updrafts in this region would form large convective, unstable regions. As the air flowed vertically, the divergence in the upper troposphere would split up and travel to the northern and southern poles. When the circulations eventually reached the colder regions, the air would become denser, form a downdraft and return to the equatorial regions along the surface. Although Hadley understood about the Coriolis acceleration, his idea (along with Halley’s) about one cell in each of the hemispheres was not correct.

**George Hadley (1685-1768), English lawyer & scientist **2
- “I think the causes of the General Trade-Winds have not been fully explained by any of those who have wrote on that subject.” (1735)
- In 1735, Hadley expounded upon the ideas of Halley.  Instead of simple currents traveling east, he envisioned a Coriolis acceleration that is latitude dependent.
- He also envisioned an "anti-trade" wind that blew to the northeast above the surface southeast trades and found that the mid-latitude westerly got their eastward velocity from sinking dense and fast air from aloft. These ideas still hold valid today.
- First to describe tropical circulation in 1753. He envisaged the heat surplus of the equatorial regions driving large-scale circulation cells consisting of air rising in the tropics and then sinking 30 degrees north and south. This sinking air would then flow back towards the equator. His simple idea was to become the basis of the general circulation of the atmosphere as it is understood today.
- Both men agreed upon the idea of upper tropospheric meridional circulations. They knew that the equatorial region would have the highest temperature and therefore the updrafts in this region would form large convective, unstable regions. As the air flowed vertically, the divergence in the upper troposphere would split up and travel to the northern and southern poles. When the circulations eventually reached the colder regions, the air would become denser, form a downdraft and return to the equatorial regions along the surface. Although Hadley understood about the Coriolis acceleration, his idea (along with Halley’s) about one cell in each of the hemispheres was not correct.

## George Hadley 
The area where both Hadley Cells met along the equator was a region of large instability and created large convective clouds. This region is called the InterTropical Convergent 					Zone (ITCZ), the convergence 					describing the surface inflow 					 of air. The flow to the higher					 latitudes gained energy & 					would eventually rise at 					locations close to latitudes 					 of 60 degrees. This rising air 					behaved similar to the rising 					area at the ITCZ, creating a 					region of low pressure and 					producing regions of higher 				precipitation. Again, the rising air 				would diverge and produce the 					final polar cell. 

**George Hadley **
- The area where both Hadley Cells met along the equator was a region of large instability and created large convective clouds. This region is called the InterTropical Convergent 					Zone (ITCZ), the convergence 					describing the surface inflow 					 of air. The flow to the higher					 latitudes gained energy & 					would eventually rise at 					locations close to latitudes 					 of 60 degrees. This rising air 					behaved similar to the rising 					area at the ITCZ, creating a 					region of low pressure and 					producing regions of higher 				precipitation. Again, the rising air 				would diverge and produce the 					final polar cell.

## Benjamin Franklin (1706-1790), U.S. founding father and experimental scientist 3
Franklin suspected that lightning was an electrical current in nature, 		and he wanted to test this idea. One way would be to see if the 		lightning would pass through metal. In 1752 he conducted his famous 		experiment by flying a key on a kite string during an electrical storm.  		
He knew lightning was powerful & dangerous & invented the lightning rod 		    to protect ships & buildings
In 1743, he observed that northeast storms begin in the southwest 		and thought it odd that storms travel in an opposite direction to their 		winds.  He predicted that a storm's course could be plotted. He later 		rode a horse through a storm and chased a whirlwind three-			quarters of a mile in order to learn more about storms. 
Franklin’s political appointments took him often to Europe. On one 		such voyage he observed the warm Gulf Stream waters by the 		temperature of the wine stored in the ship’s hull.  On a subsequent 		voyages, he mapped the Gulf Stream and recorded its surface 		temperatures and current speeds.

- Franklin suspected that lightning was an electrical current in nature, 		and he wanted to test this idea. One way would be to see if the 		lightning would pass through metal. In 1752 he conducted his famous 		experiment by flying a key on a kite string during an electrical storm.
- He knew lightning was powerful & dangerous & invented the lightning rod 		    to protect ships & buildings
- In 1743, he observed that northeast storms begin in the southwest 		and thought it odd that storms travel in an opposite direction to their 		winds.  He predicted that a storm's course could be plotted. He later 		rode a horse through a storm and chased a whirlwind three-			quarters of a mile in order to learn more about storms.** **
- Franklin’s political appointments took him often to Europe. On one 		such voyage he observed the warm Gulf Stream waters by the 		temperature of the wine stored in the ship’s hull.  On a subsequent 		voyages, he mapped the Gulf Stream and recorded its surface 		temperatures and current speeds.

***An Enlightened American***

## In 1794, Franklin wrote about Europe’s constant ‘dry fog’ 
He wrote that it so dissipated the sun's ray's that "when collected in the focus of a burning glass, they would scarce kindle brown paper.” 
Franklin correctly attributed the dry fog to a large Icelandic volcano that erupted in 1783, and he argued that the reduced solar heating was the cause of unusual cold in 1783-84. 
Franklin discussed the concept of the 				climate feedback that would result from 				increased snow cover. He understood  				brighter surfaces have greater reflectance,				 therefore exerting a cooling influence

- He wrote that it so dissipated the sun's ray's that "when collected in the focus of a burning glass, they would scarce kindle brown paper.”** **
- Franklin correctly attributed the dry fog to a large Icelandic volcano that erupted in 1783, and he argued that the reduced solar heating was the cause of unusual cold in 1783-84.
- Franklin discussed the concept of the 				climate feedback that would result from 				increased snow cover. He understood  				brighter surfaces have greater reflectance,				 therefore exerting a cooling influence

***Two of Nature’s Cooling Influences***

## Jean Baptiste Joseph Fourier (1768-1830), French mathematician 4,5

***Why is the Earth So Warm?***

- • Became interested in dissipation of heat while serving Napoleon in Egypt.  Proposed that the Earth’s atmosphere behaves like a “hothouse”
- He misunderstood how a hothouse works, and assumed that the glass let in the sun's infrared rays and reflected heat back into the structure** **
- Experimented on rate of cooling of a uniformly heated sphere. He approached this by heating a small polished iron sphere, then allowing it to cool. He found that varying the method of heating had little effect, while blackening the surface would approximately double the cooling rate.
- Transcending his theories on heat, his equations became the foundation for climate modeling today

## John Tyndall (1820-1893), natural philosopher born in Ireland 6,7
Credited for founding the science of light scattering or nephelometry. His instruments are the basis of many instru-				ments that atmospheric scientists use today 			such as fluorimeters, turbimeters and ultra-			violet spectrometers. 
His major research was in the transmission 			and absorption of gases, liquids and vapors, 			thus laying the basis for infrared spectroscopy.  		
Investigated radiant heat in1859.  He built 	the 			first ratio spectrophotometer to measure the 			absorptive powers of gases such as water 			vapor, carbon dioxide, ozone and hydro-				carbons (many of the greenhouse gases).
Demonstrated that water vapor, carbon 				dioxide and ozone are some of the best 				absorbers of heat radiation

***Light Scattering & Absorption***

**John Tyndall (1820-1893), natural philosopher born in Ireland **6,7
- Credited for founding the science of light scattering or nephelometry. His instruments are the basis of many instru-				ments that atmospheric scientists use today 			such as fluorimeters, turbimeters and ultra-			violet spectrometers.** **
- His major research was in the transmission 			and absorption of gases, liquids and vapors, 			thus laying the basis for infrared spectroscopy.
- Investigated radiant heat in1859.  He built 	the 			first ratio spectrophotometer to measure the 			absorptive powers of gases such as water 			vapor, carbon dioxide, ozone and hydro-				carbons (many of the greenhouse gases).
- Demonstrated that water vapor, carbon 				dioxide and ozone are some of the best 				absorbers of heat radiation

## John Tyndall
Concluded water vapor 						   Is the strongest absorber 					   of radiant heat and is the 						most important gas 						controlling the Earth’s 						surface air temperature. 
Speculated on how 						changes in water vapor 						and carbon dioxide 						could be related to 						climate change.

**John Tyndall**
- Concluded water vapor 						   Is the strongest absorber 					   of radiant heat and is the 						most important gas 						controlling the Earth’s 						surface air temperature.
- Speculated on how 						changes in water vapor 						and carbon dioxide 						could be related to 						climate change.

## John Tyndall
He wrote that without water vapor, Earth’s atmosphere would be “held fast in the iron grip of frost.”
Tyndall related his studies to the minimum nighttime temperatures and the formation of dew, correctly noting that dew and frost are caused by a loss of heat through radiative processes. Even saw London as a “heat island” warmer than its surroundings due to greater thermal radiation. 
Tyndall is credited with the first ever atmospheric pollution measurement using infrared and scattering measurement instruments to monitor the atmosphere. 
He discovered the Tyndall effect—the diffusion of light by large molecules and dust. Though he could not explain it theoretically, he first suggested that the reason the sky is blue is due to the scattering of the suns rays by molecules in the atmosphere
Tyndall also showed that ozone was an oxygen cluster rather than a hydrogen compound. 

- He wrote that without water vapor, Earth’s atmosphere would be “held fast in the iron grip of frost.”
- Tyndall related his studies to the minimum nighttime temperatures and the formation of dew, correctly noting that dew and frost are caused by a loss of heat through radiative processes. Even saw London as a “heat island” warmer than its surroundings due to greater thermal radiation.
- Tyndall is credited with the first ever atmospheric pollution measurement using infrared and scattering measurement instruments to monitor the atmosphere.
- He discovered the Tyndall effect—the diffusion of light by large molecules and dust. Though he could not explain it theoretically, he first suggested that the reason the sky is blue is due to the scattering of the suns rays by molecules in the atmosphere
- Tyndall also showed that ozone was an oxygen cluster rather than a hydrogen compound.** **

***Earth’s Absorptive Atmosphere ***

## Samuel Langley (1834-1906), American physicist & engineer 12,13
Invented the bolometer in 1878 (refined in 1880), which was based on the principle that electrical resistivity is affected by temperature. Composed of two thin strips of metal, a Wheatstone bridge, a battery and a galvanometer (an electrical current measuring device), the bolometer was sensitive to differences in temperature of one hundred-thousandth of a degree Celsius (.00001 C). 

- Invented the bolometer in 1878 (refined in 1880), which was based on the principle that electrical resistivity is affected by temperature. Composed of two thin strips of metal, a Wheatstone bridge, a battery and a galvanometer (an electrical current measuring device), the bolometer was sensitive to differences in temperature of one hundred-thousandth of a degree Celsius (.00001 C).

***Measuring Temperatures Remotely***

**The Bolometer**

## Samuel Langley
With the bolometer he was able to “map” the infrared portion of the solar and lunar spectrum with unprecedented accuracy.
With the spectrobolometer, Langley found the highest temperature of the Moon was about 0°C, and the lowest temperature not far from the temperature of space
Langley became deeply interested in the problem of variable solar radiation. He found that the solar constant is variable in 1904. i.e. the sun’s radiation changes over time. He also studied sunspots and tried to discern their effects on the Earth
Langley was also a pioneer in aviation
Did experiments in lift and was the first to explain how birds soar and glide without appreciable wing movement.
In 1896 Langley became the first to build heavier-than-air machines capable of unmanned and uncontrolled, but sustained flight. The first flight went 914 meters and the second 1280 meters. They used steam engines and had a wingspan of about 14 feet.

- With the bolometer he was able to “map” the infrared portion of the solar and lunar spectrum with unprecedented accuracy.
- With the spectrobolometer, Langley found the highest temperature of the Moon was about 0°C, and the lowest temperature not far from the temperature of space
- Langley became deeply interested in the problem of *variable* solar radiation. He found that the solar constant is variable in 1904. i.e. the sun’s radiation changes over time. He also studied sunspots and tried to discern their effects on the Earth
- Langley was also a pioneer in aviation
- Did experiments in lift and was the first to explain how birds soar and glide without appreciable wing movement.
- In 1896 Langley became the first to build heavier-than-air machines capable of unmanned and uncontrolled, but sustained flight. The first flight went 914 meters and the second 1280 meters. They used steam engines and had a wingspan of about 14 feet.

***Mapping the Solar Spectrum***

## Svante Arrhenius (1859-1927), Swedish physicst 14	 Theorized atmospheric CO2 rising in atmosphere due to human industry; predicted  doubling CO2 would increase average global temperature by ~ 5°C

**Svante Arrhenius (1859-1927), Swedish physicst **14**	**** **Theorized atmospheric CO2** **rising in atmosphere due to human industry; predicted  doubling CO2 would increase average global temperature by ~ 5°C

## Sir Gilbert Walker, British mathematician 8,9
As head of the Indian Meteorological Service, 			was asked in 1904 to predict the vagaries of 			India's monsoons after an 1899 famine caused 			  by monsoon failure
He noticed a seesaw relationship between 			atmospheric pressure in the eastern South 			Pacific (east of Tahiti) and the Indian Ocean 			(west of Darwin, Australia)—that is, if pressure 			was high in one region, it was usually low in 			the other and vice versa.
In 1928, Walker named this seesaw pattern 			the “Southern Oscillation” and began tracking 			pressure differences between the two regions.			 He found when pressure was very high in the 			east and low in the west, the monsoon rains in India were heavy. When the pressure difference was small, the rains failed and drought often ensued. 

- As head of the Indian Meteorological Service, 			was asked in 1904 to predict the vagaries of 			India's monsoons after an 1899 famine caused 			  by monsoon failure
- He noticed a seesaw relationship between 			atmospheric pressure in the eastern South 			Pacific (east of Tahiti) and the Indian Ocean 			(west of Darwin, Australia)—that is, if pressure 			was high in one region, it was usually low in 			the other and vice versa.
- In 1928, Walker named this seesaw pattern 			the “Southern Oscillation” and began tracking 			pressure differences between the two regions.			 He found when pressure was very high in the 			east and low in the west, the monsoon rains in India were heavy. When the pressure difference was small, the rains failed and drought often ensued.

***Early Weather Forecasting ***

## Sir Gilbert Walker
His data showed that drought conditions hit not only Australia, Indonesia, and India but also parts of sub-Saharan Africa, while there would be mild winters in Canada. 

- His data showed that drought conditions hit not only Australia, Indonesia, and India but also parts of sub-Saharan Africa, while there would be mild winters in Canada.

***Early Weather Forecasting***

## Sir Gilbert Walker
His research showed that drought conditions hit not only Australia, Indonesia, and India but also parts of sub-Saharan Africa, and at the same time there would be mild winters in Canada. 
Despite his insight and vision, Walker was unable to identify the physical processes responsible for the Southern Oscillation, and for the next three decades numerous factors conspired to dampen further research on the phenomenon. Chief among them was that from 1930 to 1950 the climate signals marking the Southern Oscillation and El Niño were much less pronounced than they had been, and interest in the subject dropped off.
Walker was publicly criticized for suggesting that climatic conditions over such widely separated regions of the globe could be linked. Walker conceded that he couldn't prove his theory, but predicted that whatever was causing the connection in weather patterns would become clear once wind patterns above ground level, which were not routinely being observed at that time, were thrown into the equation. 

**Sir Gilbert Walker**
- His research showed that drought conditions hit not only Australia, Indonesia, and India but also parts of sub-Saharan Africa, and at the same time there would be mild winters in Canada.
- Despite his insight and vision, Walker was unable to identify the physical processes responsible for the Southern Oscillation, and for the next three decades numerous factors conspired to dampen further research on the phenomenon. Chief among them was that from 1930 to 1950 the climate signals marking the Southern Oscillation and El Niño were much less pronounced than they had been, and interest in the subject dropped off.
- Walker was publicly criticized for suggesting that climatic conditions over such widely separated regions of the globe could be linked. Walker conceded that he couldn't prove his theory, but predicted that whatever was causing the connection in weather patterns would become clear once wind patterns above ground level, which were not routinely being observed at that time, were thrown into the equation.** **

## Vilhelm Bjerknes (1862-1951), Norwegian physicist & mathematician 10
His father was a scientist; at the age of 7, young Vilhelm worked with his father on his experiments in hydrodynamics. These experiences together with his college degrees led him to begin research on applying hydrodynamics and thermodynamics to large-scale motions in the atmosphere and oceans. 

- His father was a scientist; at the age of 7, young Vilhelm worked with his father on his experiments in hydrodynamics. These experiences together with his college degrees led him to begin research on applying hydrodynamics and thermodynamics to large-scale motions in the atmosphere and oceans.

***Numerical Weather Modeling***

- He was the first to propose what is called today “numerical weather modeling,” which approached forecasting using a mathematical technique called the “initial value problem,” where multiple mathematical equations describing atmospheric processes are integrated forward in time based on the current or “initial” state of the atmosphere.** **
- Due to lack of computational capacity, the calculations he envisioned were not feasible at that time. Nevertheless, Bjerknes considered weather forecasting as the principal objective of meteorological research.
- Bjkernes and his son together installed weather stations all across Norway, the data from which led to the development of their theory of Polar fronts. They put forward the theory that weather activity is concentrated in relatively narrow zones, which form the boundaries between warm and cold air masses. They called these zones "fronts," an analogy with the First World War battlefronts.

## Jacob Bjerknes 11
Bjerknes refered to the oceanic and atmospheric circulation over the tropical Pacific as a "chain reaction". He wrote "An intensifying Walker Circulation also provides for an increase of east-west temperature contrast that is the cause of the Walker Circulation in the first place." Bjerknes also noted that the interaction could operate in the opposite: a decrease in the equatorial 					easterlies diminishes the supply 					of upwelling cold water and the 					lessened east-west temperature 					gradient causes the Walker 						Circulation to slow down. He thus 					provided an explanation for the 					association of the low phase of 					the Southern Oscillation with El 					Niño as well as the association of 					the high phase with normal cold 					state of the eastern Pacific.

- Bjerknes refered to the oceanic and atmospheric circulation over the tropical Pacific as a "chain reaction". He wrote "An intensifying Walker Circulation also provides for an increase of east-west temperature contrast that is the cause of the Walker Circulation in the first place." Bjerknes also noted that the interaction could operate in the opposite: a decrease in the equatorial 					easterlies diminishes the supply 					of upwelling cold water and the 					lessened east-west temperature 					gradient causes the Walker 						Circulation to slow down. He thus 					provided an explanation for the 					association of the low phase of 					the Southern Oscillation with El 					Niño as well as the association of 					the high phase with normal cold 					state of the eastern Pacific.

***Atmospheric Circulation ***

## Milutin Milankovitch (1879-1958), Serbian astrophysicist 15,16
First known for his bridge work, Milankovitch was interned 		during WWI and during this time first began to formulate 		 his theories relating Earth’s motions and long-term climate 		change
A mathematical theory of climate based on the seasonal and 		latitudinal variations of solar radiation received by the Earth
Milankovitch Theory states that as the Earth travels around the 		sun, cyclical variations in three elements of Earth-sun geometry 		combine to produce variations in the amount of solar energy 		that reaches Earth: 

- First known for his bridge work, Milankovitch was interned 		during WWI and during this time first began to formulate 		 his theories relating Earth’s motions and long-term climate 		change
- A mathematical theory of climate based on the seasonal and 		latitudinal variations of solar radiation received by the Earth
- Milankovitch Theory states that as the Earth travels around the 		sun, cyclical variations in three elements of Earth-sun geometry 		combine to produce variations in the amount of solar energy 		that reaches Earth:** **

***Earth’s Orbital Mechanics***

- (1) Variations in the Earth's 	 orbital eccentricity—the 	 shape of the orbit around 	      the sun.

## Milutin Milankovitch

***Earth’s Orbital Mechanics***

- (2) Changes in obliquity—changes in the angle that Earth's axis makes with the plane of Earth's orbit.

- (3) Precession—the change in the direction of the Earth's axis of rotation, i.e., the axis of rotation behaves like the spin axis of a top that is winding down; hence it traces a circle on the celestial sphere over a period of time.

## Milutin Milankovitch
Using these three orbital variations, Milankovitch formulated a mathematical model that calculated latitudinal differences in insolation and the corresponding surface temperature for 600,000 years prior to the year 1800. He then correlated these changes with the growth and retreat of the Earth’s Ice Ages.
Though his first monograph on the subject was published in 1920, it was alternately ignored and refuted for about 50 years. As with many areas of science, theories predated that observational evidence. It wasn’t until 1976, when a study published in the journal Science examined deep-sea sediment cores over 450,000 revealed the relationship. 

- Using these three orbital variations, Milankovitch formulated a mathematical model that calculated latitudinal differences in insolation and the corresponding surface temperature for 600,000 years prior to the year 1800. He then correlated these changes with the growth and retreat of the Earth’s Ice Ages.
- Though his first monograph on the subject was published in 1920, it was alternately ignored and refuted for about 50 years. As with many areas of science, theories predated that observational evidence. It wasn’t until 1976, when a study published in the journal *Science* examined deep-sea sediment cores over 450,000 revealed the relationship.** **

***Earth’s Orbital Mechanics***

## Roger Revelle (1909-1991), U.S. Oceanographer 17,18 
Interested in the air-sea interface and the draw-down of carbon dioxide into the deep ocean. Searched for the saturation points and rates 
In 1957, Revelle and Hans Suess, one of the founders of radiocarbon dating, demonstrated that carbon dioxide had increased in the air as a result of the use of 				fossil fuels in a famous article published in Tellus, a 				European meteorology and oceanography journal. Under 				Revelle's leadership, the first authoritative U.S. government 			report published in which carbon dioxide from fossil fuels was 			officially recognized as a potential global problem.  

**Roger Revelle (1909-1991), U.S. Oceanographer **17,18** **
- Interested in the air-sea interface and the draw-down of carbon dioxide into the deep ocean. Searched for the saturation points and rates
- In 1957, Revelle and Hans Suess, one of the founders of radiocarbon dating, demonstrated that carbon dioxide had increased in the air as a result of the use of 				fossil fuels in a famous article published in *Tellus, *a 				European meteorology and oceanography journal. Under 				Revelle's leadership, the first authoritative U.S. government 			report published in which carbon dioxide from fossil fuels was 			officially recognized as a potential global problem.

**•** Revelle chaired the National Academy of Sciences Energy and Climate Panel in 1977, which found that about forty percent of the anthropogenic carbon dioxide has remained in the atmosphere, two-thirds of that from fossil fuel, and one-third from the clearing of forests.
- Revelle and Suess wrote their seminal paper (3) with the now legendary phrase "human beings are now carrying out a large scale geophysical experiment" that so captured the imagination of large numbers of scientists.

## Charles David Keeling, U.S. atmospheric chemist
Began measuring CO2 					levels in mid-1950s
Measured 314 ppm in 					1958, which he compared					   to George Callendar’s 					calculation of the 1900 					levels of CO2 at 290 ppm
Keeling published his 						results in 1959
While the overall trend 					continues upward, note 					the annual rise and fall, 					which illustrates our 						world’s  biosphere 						“inhaling and exhaling”  

- Began measuring CO2 					levels in mid-1950s
- Measured 314 ppm in 					1958, which he compared					   to George Callendar’s 					calculation of the 1900 					levels of CO2 at 290 ppm
- Keeling published his 						results in 1959
- While the overall trend 					continues upward, note 					the annual rise and fall, 					which illustrates our 						world’s  biosphere 						“inhaling and exhaling”

***20th Century Focus on Carbon Dioxide***

## In 1839, the first ever photos were taken in France by Daguerre and Nepce.  By 1840, the French were using photos to produce topographic maps.  
In 1858, the first aerial photos were taken of Paris by cameras mounted in a hot air balloon. There are claims that aerial reconnaissance was used during the American Civil War by hot air balloon-mounted cameras. (Perhaps, but no images survive today.)
In the 1880s, the British flew cameras mounted onto kites.
In 1903, small cameras were fixed onto carrier pigeons.
In 1909, Wilbur Wright shot the first photos from an airplane in flight.  In 1915, the British RAF collected aerial reconnaissance photos during World War I.
In 1930, the first aerial spectrophotography of the Earth was collected by Krinov and colleagues in Russia.
Infrared film first tested in 1931, dramatic advances made in 1940s. 

**In 1858, the first aerial photos were taken of Paris by cameras mounted in a hot air balloon. There are claims that aerial reconnaissance was used during the American Civil War by hot air balloon-mounted cameras. (Perhaps, but no images survive today.)**
**In the 1880s, the British flew cameras mounted onto kites.**
**In 1903, small cameras were fixed onto carrier pigeons.**
**In 1909, Wilbur Wright shot the first photos from an airplane in flight.  In 1915, the British RAF collected aerial reconnaissance photos during World War I.**
**In 1930, the first aerial spectrophotography of the Earth was collected by Krinov and colleagues in Russia.**
**Infrared film first tested in 1931, dramatic advances made in 1940s. **

***Aerial Photography & Photogrammetry ***19*** ***

## The first space-based photo taken March 7, 1947
Taken 100 miles above New Mexico, U.S., while testing captured German V-2 rockets
This photo was taken by an automatic K-12 camera, using black and white infrared film, from a Viking sounding rocket that reached a height of 227 km (141 miles). This scene spans 					across parts of New Mexico, 					Arizona, Nevada, California, & 					northwest Mexico (upper Gulf 					  of California on the left).
In 1950, scientist Otto Berg					 developed film from one of					 these tests and pieced together 					several photos into a mosaic of 					   a large tropical storm over 					Brownsville, Texas

- Taken 100 miles above New Mexico, U.S., while testing captured German V-2 rockets
- This photo was taken by an automatic K-12 camera, using black and white infrared film, from a Viking sounding rocket that reached a height of 227 km (141 miles). This scene spans 					across parts of New Mexico, 					Arizona, Nevada, California, & 					northwest Mexico (upper Gulf 					  of California on the left).
- In 1950, scientist Otto Berg					 developed film from one of					 these tests and pieced together 					several photos into a mosaic of 					   a large tropical storm over 					Brownsville, Texas

***Space-based Photography***

## Television and Infrared Observational Satellite (TIROS-1) launched on April 1, 1960
The first experimental weather satellites began with TIROS-1. The main instrument 		was a vidicon, which is a modified television camera that 	scanned through 500 lines, each containing 500 pixels. 	Shown bottom right are the first images returned from 		TIROS-1.

- The first experimental weather satellites began with TIROS-1. The main instrument 		was a vidicon, which is a modified television camera that 	scanned through 500 lines, each containing 500 pixels. 	Shown bottom right are the first images returned from 		TIROS-1.

***Early Space-based Imagery***

## During Mercury & Apollo programs, Astronauts provided us with breathtaking & scientifically interesting pictures of our home planet
Earth's cloudy surface, as seen by Alan Shepard onboard the Mercury-Redstone 3 (MR-3) spacecraft on May 5, 1961, the first U.S. manned spaceflight
The first Earthrise seen from the					 surface of the moon by the first 					Apollo Lunar landing mission 

- Earth's cloudy surface, as seen by Alan Shepard onboard the Mercury-Redstone 3 (MR-3) spacecraft on May 5, 1961, the first U.S. manned spaceflight
- The first Earthrise seen from the					 surface of the moon by the first 					Apollo Lunar landing mission

***Early Space-based Imagery***

## “Remote sensing” coined by Evelyn Pruitt in mid-1950s
The term refers to measurement or observation of an object from a distance using an artificial device without disturbing the intervening medium
Earth Resources Technology Satellite (ERTS) launched in 1972 (later renamed Landsat-1)
Idea was born when RCA approached 				terrain photographers at NASA GSFC 				  to use a Return Beam Vidicon (RBV) 				camera on an unmanned satellite to 				produce high-res imagery for geo- 				logical & other scientific purposes
The spectacular photography from the 				Apollo program largely responsible for 				providing the impetus to develop & 				launch the first Landsat satellite
Provides a continuous, consistent & high quality 30-			year data set of Earth’s land surfaces and changes 			over time. 

- The term refers to measurement or observation of an object from a distance using an artificial device without disturbing the intervening medium
**Earth Resources Technology Satellite (ERTS) launched in 1972 (later renamed Landsat-1)**
- Idea was born when RCA approached 				terrain photographers at NASA GSFC 				  to use a Return Beam Vidicon (RBV) 				camera on an unmanned satellite to 				produce high-res imagery for geo- 				logical & other scientific purposes
- The spectacular photography from the 				Apollo program largely responsible for 				providing the impetus to develop & 				launch the first Landsat satellite
- Provides a continuous, consistent & high quality 30-			year data set of Earth’s land surfaces and changes 			over time.

***Satellite Remote Sensing: Art & Science***

## The launch of Nimbus-7 in 1978 marked a milestone in providing space-based sensors for scientific research of Earth’s atmosphere on a global scale
This artist’s drawing shows the satellite’s nadir deck containing eight Earth-viewing sensors, including the first Earth Radiation Budget (ERB) experiment 				

- This artist’s drawing shows the satellite’s nadir deck containing eight Earth-viewing sensors, including the first Earth Radiation Budget (ERB) experiment

***Atmospheric Research Satellites***

## Mario Molina and Sherwood Rowland
In 1973, these U. of Cal. researchers published their theory that man-made chlorofluorocarbons (CFCs) could damage the Earth's stratospheric ozone shield. 
The theory was controversial, but 2 years later the U.S. Congress asked NASA to develop a "comprehensive program of research, technology, and monitoring of phenomena of the upper 			atmosphere.”
Ironically, the ozone "hole" over Antarctica 			wasn't discovered until May 1985, by J.C. 				Farman using a ground-based Dobson				ozone spectrophotometer. He found that 				stratospheric ozone over Halley Bay was 				about 40 percent less than what had been 			measured during the previous winter.
NASA researchers had detected the hole 				too, but were slowed to press by bad 				surface validation data

- In 1973, these U. of Cal. researchers published their theory that man-made chlorofluorocarbons (CFCs) could damage the Earth's stratospheric ozone shield.
- The theory was controversial, but 2 years later the U.S. Congress asked NASA to develop a "comprehensive program of research, technology, and monitoring of phenomena of the upper 			atmosphere.”
- Ironically, the ozone "hole" over Antarctica 			wasn't discovered until May 1985, by J.C. 				Farman using a ground-based Dobson				ozone spectrophotometer. He found that 				stratospheric ozone over Halley Bay was 				about 40 percent less than what had been 			measured during the previous winter.
- NASA researchers _**had**_ detected the hole 				too, but were slowed to press by bad 				surface validation data

***Politics, Science & Ozone Depletion***

## Toward a comprehensive, wholistic 				examination of our planet
Scientists increasingly recognized 				the 4 major spheres of the Earth’s 				environment all interact in many 				simple & complex ways.  NASA’s 				goal is to understand how these 				spheres interact so that we can 					construct computer models of the 				system, enabling us to predict 					future changes.
As the centerpiece of its Earth 					Science Enterprise, NASA’s Earth 				Observing System began in the 					early 1990s, comprised of:
A new generation of satellite sensors
A robust new data system (EOSDIS)				  
Multi-disciplinary, multi-national teams 				    of scientists

**Toward a comprehensive, wholistic ****	****	****	****	****examination of our planet**
- Scientists increasingly recognized 				the 4 major spheres of the Earth’s 				environment all interact in many 				simple & complex ways.  NASA’s 				goal is to understand how these 				spheres interact so that we can 					construct computer models of the 				system, enabling us to predict 					future changes.
- As the centerpiece of its Earth 					Science Enterprise, NASA’s Earth 				Observing System began in the 					early 1990s, comprised of:
- A new generation of satellite sensors
- A robust new data system (EOSDIS)
- Multi-disciplinary, multi-national teams 				    of scientists

## Chlorine monoxide (left) and ozone concentration (right) derived by MLS at approximately 18 km altitude on August 27, 1997, and October 10, 1997, respectively.  The high chlorine monoxide within the Antarctic polar vortex in the left-hand figure (green, yellow, and red) is directly associated with, and leads to, a reduced ozone concentration shown in the right-hand figure (purple).

- Chlorine reacts with ozone, forming chlorine monoxide & oxygen.  Chlorine monoxide reacts with oxygen to free up the original chlorine atom to further destroy ozone, setting up a vicious cycle.

## Provides a long-term global perspective on climate “teleconnections” we would not otherwise have

***Why is Space-based Remote Sensing Useful?***

## Provides the ability to zoom in on surface phenomena, such as Natural Hazards, and observe and quantify changes

**Provides the ability to zoom in on surface phenomena, such as Natural Hazards, and observe and quantify changes**

***Why is Space-based Remote Sensing Useful?***

## Space-based remote sensors allow us to observe & quantify Earth’s environments in regions of the electromagnetic spectrum to which our eyes are not sensitive

***Why is Space-based Remote Sensing Useful?***

## Human population has tripled
Humans have altered 40 percent of the Earth’s land surface
The rate of biomass burning has quadrupled—we consume an average of 175 million acres of forest & grassland annually
Levels of carbon dioxide have risen by 30 percent
We introduced chlorofluorocarbons (CFCs) into the stratosphere that destroy ozone there
Global temperatures have risen by ~ 0.5°C - 0.7°C
About 24 mm more rain will fall in 2000 than in 1900
Today, 2-3 glaciers disappear every year—Glacier Park may be renamed “No-Glacier National Park” by 2050

**Humans have altered 40 percent of the Earth’s land surface**
**The rate of biomass burning has quadrupled—we consume an average of 175 million acres of forest & grassland annually**
**Levels of carbon dioxide have risen by 30 percent**
**We introduced chlorofluorocarbons (CFCs) into the stratosphere that destroy ozone there**
**Global temperatures have risen by ~ 0.5°C - 0.7°C**
**About 24 mm more rain will fall in 2000 than in 1900**
**Today, 2-3 glaciers disappear every year—Glacier Park may be renamed “No-Glacier National Park” by 2050**

***Symptoms of Change over the Last 100 Years***

## Come explore your world in NASA’s award-winning web site, at ...

***Come explore your world in NASA’s award-winning web site, at ...***
**http://earthobservatory. ****	****          nasa.gov**

## [1] http://orca.rsmas.miami.edu/classes/mpo551/mike/ideas.html
[2] http://www.ucar.edu/communications/ucar25/forecasts.html
[3] http://www.english.udel.edu/lemay/franklin/ 
[4] http://65.107.211.206/science/fourier.html
[5] http://acd.ucar.edu/textbook/ch15/Fourier/Fourier.cite1.html
[6] http://www.tyndall.ac.uk/general/john_tyndall_biography.shtml
[7] http://www.tyndallpublications.com/johntynd.htm
[8] http://www7.nationalacademies.org/opus/El_Nino_and_La_Nina_3.html
[9] http://www.ce.berkeley.edu/~silverman/walker/walker.html
[10] http://www.copernicus.org/EGS/egs_info/bjerknes.htm
[11] http://ess.geology.ufl.edu/usra_esse/ENSO_History.html
[12] http://www.hao.ucar.edu/public/education/sp/images/langley.html
[13] http://www.clpgh.org/exhibit/neighborhoods/northside/nor_n112.html
[14] http://earthobservatory.gsfc.nasa.gov/Library/Arrhenius
[15] http://geography.aboutcom/library/weekly/aa121498.htm?once=true&
[16] http:///www.gi.alaska.edu/ScienceForum/ASF8/825.html
[17] http://scilib.ucs.edu/sio/archives/siohstry/revelle-biog.html
[18] http://www.mbari.org/ghgases/revelle/text.htm
[19] http://rst.gsfc.nasa.gov
[20] http://earthobservatory.nasa.gov

- [2] http://www.ucar.edu/communications/ucar25/forecasts.html
- [3] http://www.english.udel.edu/lemay/franklin/
- [4] http://65.107.211.206/science/fourier.html
- [5] http://acd.ucar.edu/textbook/ch15/Fourier/Fourier.cite1.html
- [6] http://www.tyndall.ac.uk/general/john_tyndall_biography.shtml
- [7] http://www.tyndallpublications.com/johntynd.htm
- [8] http://www7.nationalacademies.org/opus/El_Nino_and_La_Nina_3.html
- [9] http://www.ce.berkeley.edu/~silverman/walker/walker.html
- [10] http://www.copernicus.org/EGS/egs_info/bjerknes.htm
- [11] http://ess.geology.ufl.edu/usra_esse/ENSO_History.html
- [12] http://www.hao.ucar.edu/public/education/sp/images/langley.html
- [13] http://www.clpgh.org/exhibit/neighborhoods/northside/nor_n112.html
- [14] http://earthobservatory.gsfc.nasa.gov/Library/Arrhenius
- [15] http://geography.aboutcom/library/weekly/aa121498.htm?once=true&
- [16] http:///www.gi.alaska.edu/ScienceForum/ASF8/825.html
- [17] http://scilib.ucs.edu/sio/archives/siohstry/revelle-biog.html
- [18] http://www.mbari.org/ghgases/revelle/text.htm
- [19] http://rst.gsfc.nasa.gov
- [20] http://earthobservatory.nasa.gov

***Internet References***

## Parkinson, C. L., 1985: Breakthroughs: A Chronology of Great Achievements in Science and Mathematics, G. K. Hall & Company, Boston, 576 pp.
Gurney, R.J., J.L. Foster and C.L. Parkinson, 1993:  Atlas of Satellite Observations Related to Global Change,  Cambridge University Press, Cambridge.
Manuel, Diane, 1996: Encyclopedia of Weather and Climate, Oxford
          University Press, New York, 315 pp. 
Parkinson, C. L., 1997: Earth From Above: Using Color-Coded Satellite Images to Examine the Global Environment, University Science Books, Sausalito.
Fleming, James Rodger, 1998: Historical Perspectives on Climate Change, Oxford University Press, Oxford, 194 pp. 
Lowman, Paul D.,1999: “Landsat and Apollo: The Forgotten Legacy.” Photogrammetric Engineering & Remote Sensing. Oct 99, pp 1143-47.
Christianson, Gale E., 1999:  Greenhouse: The 200-Year Story of Global Warming. Walker & Company, New York, 305 pp.

- Gurney, R.J., J.L. Foster and C.L. Parkinson, 1993:  *Atlas of Satellite Observations Related to Global Change*,  Cambridge University Press, Cambridge.
- Manuel, Diane, 1996: *Encyclopedia of Weather and Climate*, Oxford
-           University Press, New York, 315 pp.
- Parkinson, C. L., 1997: *Earth From Above: Using Color-Coded Satellite Images to Examine the Global Environment*, University Science Books, Sausalito.
- Fleming, James Rodger, 1998: *Historical Perspectives on Climate Change*, Oxford University Press, Oxford, 194 pp.
- Lowman, Paul D.,1999: “Landsat and Apollo: The Forgotten Legacy.” *Photogrammetric Engineering & Remote Sensing*. Oct 99, pp 1143-47.
- Christianson, Gale E., 1999:  *Greenhouse: The 200-Year Story of Global Warming*. Walker & Company, New York, 305 pp.

***Recommended Further Reading***