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TECHNICAL REFERENCE DOCUMENT

UNDERSTAND, ASSESS, PREDICT, MITIGATE, AND ADAPT TO 

CLIMATE VARIABILITY AND CHANGE

1. Introduction

The Earth environment is a dynamic system undergoing continuous change on seasonal, annual, 

decadal and longer timescales. Many scientific observations indicate that the Earth may now be 

undergoing a period of more rapid change on these time scales, when compared to the historical 

record. Scientific evidence suggests that a complex interplay of natural and human-related forces 

may explain this observed recent climate variability.

2. User Requirements

To understand, assess, predict, mitigate, and adapt to such changes, a climate observing system 

must: 

• Improve knowledge of Earth’s past and present climate and environment, including 

its natural variability, and improve understanding of the causes of observed 

variability and changes; 

• Improve quantification of forces bringing about changes in Earth’s climate and 

related systems; 

• Observe climate system variables that specify the state, forcings and feedbacks 

• Reduce uncertainty in projections of how Earth’s climate system may change in 

future; 

• Incorporate/integrate observations from research/experimental observing systems 

in order to improve the representation and parameterization of climate processes in 

coupled climate prediction/projection models; 
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• Understand the sensitivity and adaptability of different natural and managed 

ecosystems and human systems to climate and related global changes; 

• Explore the uses and identify the limits of evolving knowledge to manage risks and 

opportunities related to climate variability and change. 

The climate observing system must be linked to an integrated data system that provides full and 

open access, which in turn links to tools that support the generation and access to climate 

information needed to inform decisions relating to adaptation and mitigation of climate change. 

The climate observing system, data system, associated tools, and the community of users of the 

information together will constitute the climate component of an Earth Information System (EIS), 

end goal of the integration of the Earth observing system of systems. Users of climate data and 

information include government agencies (federal, state, local), private industrie s (energy 

industries such as oil & gas, tourism, shipping, agriculture, fishing, insurance/re-insurance, etc.), 

universities, public institutions (education, recreational) and individuals, and non-governmental 

(non-profit) organizations. End-to-end support to make use of climate information is needed. 

Usage is diverse, and includes research and operational applications, policy making and 

coordinated planning for climate change adaptation and mitigation, as well as decision-making by 

businesses, organizations, and individuals, applied in local, regional, national, and international 

contexts. Coordination of federal acquisition of climate information, and support for its 

application, is a required ongoing activity of federal agencies that participate in the Climate 

Change Science Program (CCSP) and the Climate Change Technology Program (CCTP), under 

the Committee on Environmental Research (CENR) of the National Science and Technology 

Council, acting for the President’s Office of Science and Technology Policy. 

Earth Observations are urgently needed by Earth Systems Models, which are society's primary EIS 

tools for (a) integration of observations into a comprehensive analysis of the climate system; (b) 

forecasting the climate system on multiple time/space scales; and (c) simulating the impact of a 

particular gap or enhancement of the comprehensive Global Earth Observing System of Systems 

(GEOSS). Existing codes (e.g. from GFDL, NSIPP, GMAO, NCAR, NCEP, and others) are now 

transitioning to an improved architecture, the Earth System Modeling Framework, that will enable 

improved incorporation of new observations, comparison of multiple models, and testing and 

validation of new approaches to climate modeling, [e.g., see ESMF reference].

The following sections focus on capabilities and challenges related to observing, understanding 

and predicting climate change, based primarily on the CCSP Strategic Plan finalized in July 2003. 

The CCTP Strategic Plan, as well as ongoing work of the Intergovernmental Panel on Climate 

Change (IPCC) Working Group 2, will provide a sound basis for IWGEO to address important 

issues of adaptation and mitigation of climate change impacts, which are expected to come to the 

fore as IWGEO, and the GEO process, evolve.

3. Existing Capabilities and Commonalities
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Development of space-based, airborne and surface global observing capabilities has been a 

primary focus of U.S. efforts, particularly in recent years. Several new Earth-observing satellites, 

suborbital systems, surface networks, reference sites, and process studies are now producing 

unprecedented high-quality data that have led to major new insights about the Earth-climate 

system. The United States is now contributing to the development and operation of several global 

observing systems which collectively attempt to combine the data streams from both research and 

operational observing platforms to provide for a comprehensive measure of climate system 

variability and climate change processes. These systems provide a baseline Earth observing 

system and include: NASA, NOAA and USGS Earth-observing satellites; the global component of 

the Integrated Ocean Observing System; the Global Climate Observing System (GCOS) sponsored 

by the World Meteorological Organization (WMO); the Global Ocean Observing System (GOOS) 

sponsored by Intergovernmental Oceanographic Commission (IOC); and the Global Terrestrial 

Observing System (GTOS) sponsored by the Food and Agriculture Organization (FAO). Table 1 

is the GCOS list of essential climate variables, based on the GCOS Second Adequacy Report, 

April 2003. [See http://www.wmo.ch/web/gcos/gcoshome.html ] This set of required observables 

provides an excellent baseline, but will clearly need to be augmented. For example, incoming solar 

irradiance is listed, but also needed are in situ measurements of profiles of radiative fluxes in the 

atmosphere. Additional extensions are needed for atmosphere, ocean and terrestrial variables. 

Domain Essential Climate Variables

Atmospheric (over land, sea and ice) Surface: Air temperature, Precipitation, Air 

pressure, Surface radiation budget, Wind speed 

and direction, Water vapour.

Upper-air: Earth radiation budget (including 

solar irradiance), Upper-air temperature 

(including MSU radiances), Wind speed and

direction, Water vapour, Cloud properties.

Composition: Carbon dioxide, Methane, 

Ozone, Other long-lived greenhouse

gases, Aerosol properties.

Oceanic Surface: Sea-surface temperature, Sea-surface 

salinity, Sea level, Sea state, Sea ice, Current, 

Ocean colour (for biological activity), Carbon 

dioxide partial pressure. 

Sub-surface: Temperature, Salinity, Current, 

Nutrients, Carbon, Ocean tracers,

Phytoplankton.

Terrestrial River discharge, Water use, Ground water, 

Lake levels, Snow cover, Glaciers and ice caps, 

Permafrost and seasonally-frozen ground, 

Albedo, Land cover (including vegetation type), 

Fraction of absorbed photosynthetically active

radiation (FAPAR), Leaf area index (LAI), 
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Biomass, Fire disturbance.

Table 1 GCOS List of Essential Climate Variables,

A process for updating these variables needs to be established as we learn more about the climate 

system. Appendix 12.1, from Chapter 12 of the CCSP Strategic Plan [see 

http://www.climatescience.gov/Library/stratplan2003/final/ccspstratplan2003-chap12.htm] 

subdivides required climate variables into those specifying the “State” and those specifying the 

“Forcing/Feedback” of the climate system, and further identifies measurements made by surface, 

airborne and space-based instruments, respectively, for which operationa l or systematic (research) 

observing systems/networks and international programs exist. A current inventory of U.S. systems 

contributing to global climate observing, and related to the atmospheric, oceanic, and terrestrial 

climate subsystems, can be found in the U.S. Detailed National Report on Systematic 

Observations for Climate [August 2001, see http://www.eis.noaa.gov/gcos/soc_long.pdf]. 

Required observed variables include benchmark large-scale climate observations such as the total 

radiative energy output from the Sun that drives Earth’s climate system, the Earth’s global average 

surface temperature, the atmospheric concentration of CO2 and other atmospheric constituents, as 

well as climate variables such as precipitation, land use, and land cover, tha t undergo regional and 

local changes that have significant environmental and human impacts. In order to meet climate 

requirements, monitoring systems for climate must adhere to the 10 GCOS climate monitoring 

principles listed in CCSP Appendix 12.4. These were adopted in paraphrased form by the 

Conference of the Parties to the UN Framework Convention on Climate Change through Decision 

5/CP.5 of COP-5 at Bonn in November 1999. For satellite systems, CCSP Appendix 12.4 specifies 

a further 10 principles to ensure that observations meet the required stringent standards of 

calibration and sampling necessary for useful climate applications.

4. Major Gaps and Challenge

The CCSP Strategic Plan dedicated separate chapters to each of seven climate research elements 

that parallel subcommittees of the CENR. Each element has an associated working group within 

CCSP, which has identified challenges and priorities, documented in detailed published plans. By 

chapter number, the research elements are [3] atmospheric composition; [4] climate variability and 

change; [5] water cycle; [6] land use/land cover change; [7] carbon cycle; [8] ecosystems; and [9] 

human contributions and responses to environmental change. Themes associated with each 

research element that have unique observational challenges include: [3] aerosol, temperature, [4] 

polar climate/feedback, radiation budget, and paleoclimate. Collectively, all elements raise 

challenges associated with human dimensions themes, especially [6], [8] and [9]. 

A critical challenge is to maintain current observing capabilities that already exist in each of these 

areas. For example, maintenance of the observational record (column and profile) of stratospheric 

ozone is essential so that the effects of climate change on the nature and timing of expected ozone 
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recovery can be discerned. Other key variables requiring maintenance include atmospheric carbon 

dioxide and global surface temperature. Potential gaps in continuity needing particular attention 

are described below in 5.2. Since the value of existing climate datasets greatly increases as the 

record is extended in time, it is imperative that existing observing capabilities are maintained and 

improved. At the same time new requirements must be incorporated. 

We focus below on existing and new capabilities that most urgently need attention, while keeping 

in mind the need to continue doing what is already being done well. Table 2 identifies in column 1 

each of the above themes by a brief title, with the relevant chapter of the CCSP Strategic Plan [in 

brackets], and in column 2 observables, or variables, whose measurement represent significant 

challenges that must be met by future climate observing systems. In columns 3, 4 and 5 are 

satellite, suborbital, and sur face observing systems, respectively, that have the potential to meet 

these challenges. 

It should be noted that the observations that need to be made under any one theme frequently 

overlap with those that need to be made under one or more of the other themes of the CCSP. Thus 

observations of vegetation are required for the water cycle (evapotranspiration moisture fluxes) as 

well as the carbon cycle (carbon budget) and ecosystems (biodiversity) etc. Similarly, radiation 

budget parameters are required by nearly all themes and for quantification of forcing and 

feedbacks within and between components of the climate system. Precipitation, though identified 

under the water cycle is also needed by the land, ecosystems, human dimensions, carbon, and 

polar themes. 

Table 2 provides both research, transitional, and operational satellite observing systems; the latter 

which provide for long term satellite observations, and this is a direct tie to the transition of 

instruments developed in a research mode and trans itioned to sustained operations. Such initial 

technologies are typically developed by NASA and then put into sustained operations by NOAA. 

The archival of the vast amount of this data is an immense undertaking with large cost and 

management issues which CCSP agencies are address in coordinated activities. 

Themes / 

Needs Variables

Satellite 

Observing 

Systems

Suborbital 

Observing Systems

Surface 

Observing 

Systems

Land/ 

Ecosystems/ 

Human [6, 8, 

9] 

Land Use and 

Cover, Sea Level 

Landsat 

Continuity with 

Long-term 

Acquisition Plan 

UAV 

hyperspectral/Lidar/ 

SAR/thermal 

mapping system 

LTER, Tide 

Gauge and 

Experimental 

Watershed 

Networks 

Polar 

Climate and 

Feedback [4] 

Land ansd Sea 

Ice Thickness, 

Ice mass balance 

GLAS/IceSat 

CMIS 

Low, slow 

geostationary polar 

mapping system 

Surface Polar 

Observatories 
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Aerosol [3] Natural and 

Anthropogenic, 

Cloud processes 

and structure 

Polarimeter, APS High spacetime 

resolution, sfc to 

stratosphere, all 

weather profiling 

system 

Aeronet, 

Ozonesonde, 

Third World 

Capacity Building 

Carbon 

Cycle [7] 

Ocean Carbon 

Fluxes, Heat 

Content 

Orbiting Carbon 

Observatory 

Low, slow UAV and 

AUV system 

Ocean Reference 

Stations 

Water Cycle 

[5] 

Cloud processes 

and structure, 

Precipitation, 

Soil Moisture, 

Water Vapor, 

River Discharge, 

Groundwater 

CloudSat, 

Calipso, AIRS, 

AMSR-E, GPM, 

VIIRS, CMIS, 

CrIS, ATMS, 

HYDROS, 

COSMIC (GPS 

radio 

occultation) 

High spacetime 

resolution, sfc to 

stratosphere, all 

weather profiling 

system 

GUAN, GPS 

Integrated Water 

Vapor, CRN, 

USGS 

Streamflow Data 

Network, USGS 

Groundwater 

Climate Response 

Network, 

USDA/USGS 

Experimental 

Watershed 

Networks

ARM Sites

Radiation 

Budget [4] 

Solar and Earth

Radiative Fluxes 

at Top-ofAtmosphere and 

Surface 

SORCE + 

CERES followon missions, total 

and spectral 

measurements, 

TIM, SIM 

High resolution 

profiles of long and 

shortwave radiative 

fluxes [surface to 

stratosphere] 

UV Calibration 

Facility, 

SURFRAD, 

BSRN, SURFX, 

ARM Sites 

Temperature 

[3] 

Stratosphere, 

Troposphere and 

Surface 

Temperature

 AMSR-E 

follow-on, 

CMIS, COSMIC 

and other radio 

occultation 

missions 

High resolution 

global temperature 

profiling system 

High Altitude 

Surface 

Observing 

Network, Climate 

Reference 

Network 

Paleoclimate 

[4] 

Ocean Corals, 

Temperature and 

Composition 

Indicators

AUV ocean floor 

sampler, UAV 

hyperspectral 

monitoring of ocean 

coral reefs

Coral & Ocean 

Cores, High 

sedimentation 

rate deep sea 

cores, Integrated 

Q/C Data System

Table 2: Meeting Climate Challenges
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The above table is ordered from the top down, beginning with themes in which the human 

dimension is most evident, to those having the most evident benefit to scientific understanding. 

Prioritizing contributions to these themes is a multi-dimensional problem that cannot be solved by 

linear approaches, and that must maintain a balance between science and applications as discussed 

in Chapter 1 of the CCSP Strategic Plan. Near term research priorities given focus by CCSP are 

(1) aerosols; (2) polar climate and feedbacks; and (3) carbon sources and sinks. These are most 

directly related to the first four areas listed in Table 2, but are also connected to each of the other 

areas. Observational elements that have a high degree of readiness, including heritage systems, 

have been identified to meet each of the above challenges, as indicated in the three rightmost 

columns, for satellite, suborbital and surface observing systems. Moreover, it is underscored that 

the baseline or reference station networks identified in column 4 are required to maintain a 

"reference" monitoring system for a few key climate system parameters. They are not in 

themselves sufficient to observe or monitor the entirety of the climate system. Thus, an integrated 

approach is required to the subject of observing systems, namely one that combines the long-term 

data and information that captures trends and change in climate together with more detailed 

observations and models of all other aspects of the climate system. For the latter, a combination 

of research-based satellite and in situ suborbital and surface-based observing systems, together 

with operational systems, need to be used in conjunction with the "reference" network. 

Each of the above observing system elements consists of a spaceborne element that provides 

adequate global coverage and space-time resolution required to meet user needs, coupled with a 

related surface element providing process studies, va lidation, and appropriate local sampling. In 

addition, linking the local long duration space-time sampling of surface networks with the global 

sampling of the spaceborne systems requires a variety of innovative atmospheric and oceanic 

piloted and unpiloted platforms, including remotely piloted aircraft, long-duration balloons, kites, 

and other innovative surface platforms, as well as traditional aircraft, balloons, ships, buoys, and 

tide gauges. 

Continuity of the Landsat data stream is crucial. The Landsat program has provided an 

uninterrupted 30-year record of the global land area in the form of high resolution, multispectral 

digital images acquired from a series of satellites. Two Landsat satellites remain in operation 

today, Landsats 5 and 7. Landsat 5 was launched in 1984 and is operating 17 years beyond its 

three-year design life. Its fuel will be depleted by 2008. Landsat 7 was launched in April 1999 and 

reached the end of its five-year design life in 2004. The Landsat 7 sensor, the Enhanced Thematic 

Mapper-Plus (ETM+), suffered a malfunction in May 2003, which produces intermittent gaps in 

the acquired images. At a time when the growing population is altering the land surface at a scale 

unprecedented in history, the launch of a follow-on Landsat satellite at the earliest possible date is 

a high priority. 

Both the GCOS Second Adequacy Report and the CCSP Strategic Plan call for complete global 

coverage of the oceans with moored, drifting, and ship based networks. Without urgent action to 

address the global ocean, the nations of the world will lack the information necessary to 

effectively plan for and manage their response to climate change. The highest priority for the 

global component of the Integrated Ocean Observing System is sustained global coverage. 
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Climate information derivable from the above observational enhancements includes: 

• Geographic extent of human impacts on the environment 

• Elevation maps depicting areas vulnerable to sea level rise 

• Global fluxes of CO2, between air and sea, air and land, within oceans, from land 

to ocean Changes in soil moisture and runoff, and tools to predict and adapt to 

drought 

• Changes in aerosol, cloud cover, precipitation, global energy budget, and their 

relationships 

• Variability and change in ice thickness and sea level, the ocean's storage and global 

transport of heat, and the ocean-atmosphere exchange of heat and fresh water 

• Integrated paleoclimatic database for evaluation of climate models. 

This subset of essential climate variables, identified above as observational challenges, also 

contributes to other themes. This is indicated in the following “crosswalk” table, where the first 

column lists the above selected variables, the rows refer to the chapter themes, and each “X” 

indicates a contribution of a selected climate variable to one of the chapter themes. Note that 

almost every row shows contributions in a majority of the chapter themes. See Appendix I for a 

more complete crosswalk that includes the above identified essential climate variables, of which 

the challenge areas are a subset. 

IWGEO CHAPTER 4.0 

THEMES Weather Disaster Ocean Climate Agric Health Ecosys Water Energy

Land Cover and Use X X X X X

Coastal Processes (e.g., 

Sea Level) X X X X X X X

Glaciers and Ice Caps X X X X X X

Sea Ice X X X X X X

Aerosol X X X X X X X

Carbon/CO2/pCO2 X X X X X X X

Water Vapor (Surface 

and Upper Air) X X X X X X

Cloud Properties X X X X X

Precipitation X X X X X X X X X

Solar, Earth, TOA & 

Surface Radiation X X X X X X X X X
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Air Temperature 

Profiles X X X X X X X X X

Ocean Temperature 

and Salinity X X X X X X

Paleoclimate X X X X X

Table 3 –Subset of Essential Climate Variables

There are many observing systems measuring important weather and climate related observations 

(e.g., Earth observing system satellites, climate reference network, ASOS, and COOP). Climate 

requires highly precise calibrated long term data that grow in value as data ages, while weather 

needs near real time data that rapidly lose value with time. Climate is also sensitive to slowly 

changing variables not of primary importance to weather. The future climate observing system of 

systems must meet unique climate observing requirements. 

Ensuring the longevity and continuity of satellite observations is a priority. One example 

identified above is the need to continue the long record of global seasonally refreshed Landsat 

data, meeting or exceeding current calibration and validation. This datastream meets a wide 

variety of needs for those studying the human dimensions of climate change, and its continuity is a 

priority. Another example is the continuity of the satellite altimetry record started with TOPEX 

and continuing with JASON-1, for monitoring ocean circulation, and for the record being obtained 

on regional and global mean sea level. Although the altimetry record is only a little over a decade 

in length, the technology offers promise in developing estimates of global sea level trends in 

conjunction with continued operation of key tide station locations. 

A third example is continuation of the radiation budget record, one of the longest and most useful 

of our global climate records. The record began in 1978 with the Nimbus 7 spacecraft and has 

been maintained with instrument overlap through the present NASA Terra and Aqua missions. 

The radiation budget record is critical for separating external solar forcing from internal forcings, 

and for verification of climate model predictions of cloud/radiation feedbacks. Cloud feedbacks 

are the largest uncertainty in estimates of climate sensitivity and therefore in predicting future 

climate change (IPCC, 2001, NRC, 2003, CCSP, 2003). Cloud/radiation feedbacks currently are 

uncertain to at least a factor of 3. A recent U.S. multi-agency analysis of satellite calibration and 

stability requirements for the climate data records (Ohring et al., 2003) showed that overlapping 

observations of the radiation budget record are critical to achieving the decadal instrument 

stability necessary to directly observe cloud/climate feedback. The international Global Climate 

Observing System (GCOS) Second Adequacy Report (2002) reached a similar conclusion. 

Similar related needs exist for the surface networks. Important examples being used and planned 

as essential climate networks are USDA-NRCS SNOwTelemetry (SNOTEL) and Soil Climate 

Analysis Network (SCAN), as well as other important mesonets (RAWS, High Plains, etc.) There 

is a pressing need to evaluate the nature and extent of (land-surface) hydrologic change and its 

particular effect on climate. Most (>75% by one accounting) major rivers in the Northern 

Hemisphere have been substantially modified by society, changing their discharge amounts and 

seasonality, which modifies distributions of inundation, evaporation, and transpiration on regional 

scales. The modernized COOP will be a network that can serve the nation as the backbone of an 
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Integr ated Surface Observing System (ISOS). It will be the sustaining factor around which all 

surface environmental monitoring networks are integrated. The network will provide high-quality 

real-time weather, water, and climate information, and possibly air qua lity and biochemical 

hazard data. The Climate Reference Network (CRN) will provide the highest possible benchmark 

quality climate data for calibration of the ISOS. Three activities taking place today are related to 

the development of a system-of-systems approach to surface weather and climate monitoring. 

First, as the COOP modernization moves forward, the experience of CRN in the selection of 

instruments is being fully utilized. Second, a Memorandum of Agreement (MOA) is being 

developed related to the operation of the NOAA/NESDIS/National Climatic Data Center (NCDC) 

CRN and NOAA/NWS COOP network. And third, a national network of ground-based GPS 

receivers is emerging and is producing accurate and temporally continuous measurements of total 

water vapor in the atmospheric column. This information will be useful in weather prediction as 

well as in monitoring climate variability and trends. 

Subsequent to this MOA it is expected, once the 100 CRN stations are fully deployed across the 

continguous U.S. (FY07), that the NWS will work with NESDIS and OAR to develop a 

maintenance agreement for the CRN and modernized COOP. Whether maintenance for the CRN 

can be provided by the private sector, State Climatologists, Regional Climate Centers, NOAA 

personnel, or a combination of these, will be addressed over the next two Fiscal Years. This will 

require substantial community discussion including our Science Advisory Board Working Groups 

on Climate. NOAA is committed to developing a single integrated data ingest and quality control 

system for all the surface weather and climate data NOAA uses. At the present time the NCDC 

operates a comprehensive data quality control system and has protoyped an integrated surface, in

situ, model, and space-based observations in our quality control, which will be useful in the ISOS 

framework. NWS and NESDIS are working to ensure a seamless end-to-end surface observing 

suite. 
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Figure 1

The above sections have briefly summarized the diverse array of observational systems, as well as 

the wide variety of user groups and applications. An integrated system must provide for a 

seamless link between the providers and users of climate information systems. Figure 1 

summarizes the issues in terms of transforma tions of raw observational data from many sources, 

from the long term record of weather observations, observations collected as part of research 

investigations, highly precise continuous observations of variables collected expressly to 

document long term climate change, to paleoclimate observations. Such data requires a 

comprehensive and reliable data management archive, coupled to tools to derive information 

products, a system for distribution, support for user interactions with the information products, and 

decision support tools that provide for user feedback to maintain and improve the end-to-end 

system. Climate observation systems must provide for integration of the data in the full end-toend system, that meets the required stringent standards of calibration, sampling and accuracy 

necessary for useful climate applications (as discussed in section 2), stability needed to maintain 

ongoing data archival, and processes for improvement that take into account user feedback.

5. Future Earth Observation Systems that May Fill Gaps

Since 1998, Parties to the United Nations Framework Convention on Climate Change (UNFCCC) 

have noted the decline in the global climate observing capability, and have urged Parties to (a) 

undertake programs of systematic climate observations and (b) strengthen their capabilities in the 

collection, exchange, and utilization of environmental data and information. A wide range of 
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global observations are needed to understand and monitor Earth processes that contribute to 

climate, and an assessment of the effects of human and natural activities cannot be made by a 

single program, organization, or country. 

Future Earth observing systems will learn from, leverage, and extend the current observing 

capacity, summarized in CCSP Appendix 12. The CCSP Strategic Plan is a framework to address 

some of the most complex questions and problems that the United States and the world now face. 

The issue of climate variability and change, the level and affects of potential human contributions 

to these issues and how we adapt and manage these impending forces is a capstone issue for our 

generation and those to follow. This plan addresses these challenges by leveraging existing 

knowledge to learn new things, building bridges across communities and scientific disciplines to 

gain greater insight, reaching out to decision-makers, and maintaining an open and transparent 

process to ensure that our partners are heard and we are hearing them. 

Satellite observations provide a unique vantage point from which to study the Earth system. 

Moreover, they enable observation of rapid and/or remote changes, and provide a global 

perspective on regional and coastal changes. The Earth science community has come to rely on a 

suite of research satellites, such as NASA's Earth Observing System (EOS) missions, and 

operational missions, such as NOAA's Polar-orbiting Operational Environmental Satellites 

(POES). The National Polar-orbiting Operational Environmental Satellite System (NPOESS), with 

its more capable satellite instruments and stable Earth orbits, represents a significant opportunity 

to increase the usage of satellite data in climate research. NPOESS, and its pathfinder mission the 

NPOESS Preparatory Project (NPP), are primarily deployed in support of weather observations, 

but some climate requirements have been incorporated. NPP and NPOESS straddle the line 

between weather and climate observing and while they will not answer all climate questions, the 

deployment of these systems is essential in the transition from research to operations for a number 

of instruments deployed on earlier research missions (e.g., EOS series). GPS radio occultation 

(RO) soundings from the CHAllenging Minisatellite Payload (CHAMP), SAC-C, and COSMIC 

satellites, along with other RO missions will complement the Infrared (IR) and Microwave 

Sounding Unit (MSU) soundings, greatly improving the quality of the climate and weather 

analyses. Review processes will be needed to assure that the GCOS climate monitoring standards 

are met. 

A globally coordinated network of demonstration ecological observing systems is needed to 

document long-term trends in ecosystem status and to serve as test beds for research and 

technology development to improve ecosystem observations in the future. Data from existing 

satellites must be fully exploited to observe ecosystem status, and ecosystem observation 

requirements must be considered in design of future satellites. 

• Establish science planning teams to define core ecological observing system 

requirements for terrestrial, marine, and aquatic application (build on NSF-NEON 

and NOAA Ecosystems Observations plans among others) 
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• Identify existing sites nationally and internationally that could serve as the basis for 

the network of ecological observing systems 

• Identify and monitor climate-sensitive 'sentinel species' in terrestrial, marine, and 

aquatic ecosystems that integrate climate signals over time and space; and that may 

serve as 'early warning indicators' of climate change 

• Initiate accelerated research to build the scientific foundation and enhanced 

technological capability for detecting and forecasting responses of ecosystems to 

multiple environmental changes 

• Collect and cross-calibrate all ecosystem-relevant remote sensing data to create and 

regularly update a global atlas of ecosystem status at the highest possible resolution 

Information on aerosols represents one of the largest gaps in our understanding of potential 

climate change. Aerosols (airborne fine particles) arise from both natural (dust) and humaninfluenced (chemical emissions) sources. Aerosols influence the climate system in two major

ways: (1) scattering (climate cooling) and absorption (climate warming) of radiation and (2) 

altering the brightness and amount of clouds (changing the natural radiation pathways), as well as 

precipitation characteristics. Climate models must adequately represent both if there are to 

meaningful projections of future of climate change by natural or human-caused agents. The 2001 

IPCC assessment of the Intergovernmental Panel on Climate Change (IPCC) places the aerosols–

climate interaction as the single largest uncertainty in the radiative forcing of climate change. 

Further, the science community and the U.S. Climate Change Science Program (CCSP) deem a 

better understanding of aerosols and climate to be one of the top three current research needs, with 

the largest uncertainty being the aerosol-cloud-climate interactions. The information needs are 

threefold: (i) global observations of aerosol properties and distributions, (ii) an understanding of 

the processes that link emissions of aerosols and precursors to global aerosols distributions and 

processes, and (iii) improved and evaluated models that link aerosol characteristics to the climate 

system. 

The delivery of climate data and services has a significant research component. The science 

community is continuing to investigate the complexities of the climate system, expanding the 

types of data that are needed, refining the requirements for the measurements in terms of spatial 

and temporal resolution and other aspects of data quality. Climate research is not as mature as 

weather forecasting, where data product requirements are well defined. Data products that are 

useful for operational needs, such as short-term forecasting, generally do not meet the needs of the 

Earth science community, especially for the study of climate-related processes. Long-term 

archiving, careful calibration, and regular reprocessing with state-of-the-art algorithms are critical 

for climate research applications. Operational needs are characterized by rapid, predictable and 

extremely reliable delivery schedules of standardized data products. To serve the needs of climate 

research, the future observing system must provide the necessary climate research services and 
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functions, and the climate data management system must be designed with long-term operational 

needs in mind.

6. Interagency and International Partnerships

The United States and International partners coordinate the implementation of the Climate 

Variability and Change strategic vision. Our Changing Planet FY 2003 illustrates the broad interagency involvement of a cross-section of relevant U.S. federal agencies, coordinated at 

U.S. cabinet level. U.S. CLIVAR has in place a nucleus of scientific and programmatic elements, 

and strong linkages with the weather prediction community will advance capabilities to address 

issues of high societal relevance. The cadre of regional climate centers and state climatologists 

help ensure that regional and user expertise is represented in the development of effective 

frameworks for making climate information available. International research programs such as the 

World Climate Research Programme (WCRP) and its projects Climate Variability and 

Predictability (CLIVAR), Stratospheric Processes and their Role in Climate (SPARC), Climate 

and Cryosphere (CliC), the Global Energy and Water Cycle Experiment (GEWEX), as well as the 

International Geosphere-Biosphere Programme (IGBP) are critical for developing global 

infrastructure. GCOS has fostered the integration of key elements The IGOS Partnership (IGOS-P)

focuses specifically on the observations in providing information for decision-making. The 

implementation panels of the Joint WMO/IOC Technical Commission for Oceanography and 

Marine Meteorology are particularly well positioned to deploy and sustain the in situ ocean 

networks

Partnerships between governmental and non-governmental, including commercial, non-profit, and 

universities, will continue to be essential in all areas of this plan. Transfer of capabilities should be 

encouraged in both directions, as “spin-offs” from government to the private sector, and as 

infusion of new technology into government activities. Enhanced collaboration between federal 

data centers and external (university, commercial, and non-profit) data service providers is needed. 

This collaboration will build on the strong foundation provided by existing dis tributed systems, 

encompassing the data centers established by federal science agencies, including NASA, NOAA, 

DOE, U.S. Department of Agriculture, the Environmental Protection Agency, USGS data centers, 

and NSF. CCSP’s data management plan also calls for expanding partnerships with foreign 

governments, intergovernmental agencies, and international scientific bodies and data networks to 

provide data that are needed to address the international character of research and decision 

making. These collaborations should improve access to regional, state, and local data.

7. U.S. Capacity Building Needs

A primary objective of the CCSP is to develop information and scientific capacity needed to 

sharpen qualitative and quantitative understanding through interconnected observations, data 

assimilation, and modeling activities. The program will address the potential for future changes in 

extreme events and uncertainty regarding potential rapid climate change. The CCSP will build on 

existing U.S. strengths in climate research and modeling, and enhance capacity for development of 
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high-end coupled climate and Earth system models. Enhancements in the observational system 

will focus on the related distributions of aerosols, clouds, and rainfall; on closing the budgets of 

carbon and nitrogen; and on determining crucial climate feedbacks, especially in the sensitive 

Arctic and Antarctic climatic regions. A rigorous approach to quality control that will assess the 

precision and accuracy in accordance with climate modeling principles is essential. 

Land Use and Land Cover Change (LULCC) research requires global multi-resolution Earth 

observations that are coupled with in situ measurements. These observations need to document 

baseline global land use and land cover types and patterns across multiple spatial and temporal 

scales. 

To achieve the goals of LULCC, we require the following data for developing the tools, methods, 

and knowledge that better characterize historic and current land use and land cover attributes and 

dynamics: 

• Multi-spectral imagery with different spatial (regional, national and global) and 

temporal resolutions (daily to annual). Especially critical are: 

• High resolution (10-30m resolution) multi-spectral imagery that ensures continuity 

and comparability with the 32 year Landsat record. 

• Daily calibrated global moderate resolution (100-1000m) resolution multi-spectral 

imagery that is compatible with the historical AVHRR and MODIS. 

• Very high resolution (<10m resolution) multi-spectral imagery with improved 

sensor calibration is needed for local characterization and validation of global 

datasets. 

• Hyperspectral, radar, and related advanced technology imagery for detailed 

characterization of landscape condition and processes. 

• Field data that are useful for understanding current and projected changes in 

socioeconomic and ecological processes. Specifically, we require: 

• Expanded ground-based environmental inventory and ecological process data 

collection programs (e.g., forest inventory, land management practices, land use 

change, water quality, etc.) that contribute to the explanation of the rates, causes, 

and consequences of landscape change. 
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• Socioeconomic data and land use histories to develop an understanding of primary 

drivers of landscape change and to support the development of projections of 

future land use and land cover 

Data on disturbances such as fire and flooding that alter land cover and land use are needed, as 

well as compilation of local datasets, and development of a standardized database linking local 

data to national and global land cover data products. 

The global-mean temperature at the Earth’s surface is estimated to have risen by 0.25 to 0.4 ° 

Celsius (C) during the past 20 years. However, satellite measurements of radiances indicate that 

the temperature of the lower mid-troposphere (the atmospheric layer extending from the Earth’s 

surface up to about 8 km) has exhibited a smaller rise of approximately 0.0 to 0.2° C during this 

period. Estimates of the temperature trends of the same atmospheric layer based on balloon-borne 

observations (i.e., radiosondes) tend to agree with those inferred from the satellite observations. 

These apparently conflicting trends between surface and lower troposphere have caused some to 

question the magnitude of the surface warming and has led to continuing studies of temperature 

trends, analysis techniques of surface, airborne and satellite remote sensing, and radiosonde data 

sets, and a need for sustained and improved observations. 

A new active atmospheric sounding technique, radio occultation, which uses the Global 

Positioning System (GPS), has been shown to provide accurate and high-vertical resolution allweather soundings of refractivity, which is a function of temperature, water vapor and pressure. 

The Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC), a joint 

U.S.-Taiwan mission, will consist of six small satellites in low Earth orbit, and will provide 

approximately 2500 soundings per day globally over a five-year period beginning in late 2005. 

These soundings will complement microwave and IR sounders such as MSU, AMSR-E and AIRS, 

and these independent systems when assimilated together in models will produce global 

atmospheric temperature and water vapor fields of unprecedented accuracy and resolution, greatly 

reducing the uncertainty in atmospheric temperature and water vapor variability and trends. 

In addition to improvements in accuracy of observations, it is essential that the measurements 

from the numerous disparate observing subsystems be consistently and effectively combined to 

produce a state-of-the-art climate analysis. Such a climate analysis is achieved through the 

assimilation of the observations into numerical models of the climate system. In order to achieve 

the full benefits of the many different observing systems, it is essential that data assimilation 

capabilities be applied to construct ongoing climate analyses and that, as these techniques are 

refined, periodic reanalyses be conducted to improve our descriptions and understanding of past 

climate variability, for example, over the past 50 to 150 years. The first-generation of climate 

analyses and climate reanalyses have already demonstrated their tremendous value to climate 

scientists and end users by synthesizing and integrating the basic observations together in a model 

to provide a consistent picture of the climate system. Continued development and improvement in 

climate analyses and periodic reanalyses must be considered as just as fundamental to a complete 

climate observing system as improvements in the observational sub-systems themselves. 
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Modeling research is also required to improve simulations of seasonal-to-interannual variability in 

global climate models, and to improve seasonal-to-interannual climate predictions. Access to 

model products, predictions, and tailored value-added information must be provided to the 

decision-making community to foster progress in utilizing prediction capabilities. Efforts should 

be focused on key regions/phenomena that are especially vulnerable to abrupt climate change, 

such as the tropics, the Arctic and Antarctic regions, and the ocean thermohaline circulation. 

Continuing development of ens emble-based approaches will be essential in order to improve 

probability estimates of extreme events. Finally, it is essential that the Ocean Observing System 

for climate be completely implemented as currently planned through FY 2010. 

Capacity building from the U.S. and other developed countries to meet the needs of the developing 

world will continue to be critical. Landsat observations have helped developing nations better 

understand usage of their land resources, and maintenance of this long satellite heritage is a high 

priority. The future Landsat system must maintain global seasonal cloud-free sampling with a 

long-term acquisition strategy, provide for wide and open distribution, and for information and 

decision support tools. 

Networks to measure atmospheric constituents have contributed a global database of important 

information on greenhouse gases. The oceanographic community has successfully engaged coastal 

nations to participate in observing. International programs addressing terrestrial processes have 

demonstrated similar successes in observing ecosystems. The United States can contribute further 

by evaluating existing networks’ capability to meet established climate requirements; improving 

existing networks through direct contributions to international programs; forming partnerships 

with other developed countries to make directed investments to meet developing country 

inadequacies; providing direct assistance through U.S. programs of aid to specific developing 

country activities; and continuing to expand collaborative international scientific programs that 

address critical climate variables. 

Understanding the current extent and future impact of the human impact on climate change 

represents one of the most important objectives in modern scientific research. The two to fourfold 

uncertainty in estimates of the aerosol radiative forcing via the direct and indirect aerosol effects is 

one of the major sources of errors in climate change simulations. Major improvements to climate 

model treatments of aerosol-cloud-radiation interactions are needed to reduce the large 

uncertainties in climate model predictions of the human impact. Direct observations of aerosol 

physical and chemical properties and their interaction with clouds and precipitation are urgently 

needed to estimate the aerosol forcing directly from observations and to improve model treatments 

of aerosol forcing. 

A program such as the Atmospheric Brown Cloud (ABC) project coordinated by the Scripps 

Institution of Oceanography at the University of California, San Diego is an excellent example of 

international research effort involving NOAA as well as partners from India, Japan, China, and 

other associated nations. ABC focuses on linking together long-term aerosol and radiation 

measurements with remote sensing and computer modeling, which could be considered in this 

area. The Brown cloud phenomenon is a worldwide phenomenon that does affect the U.S., and 

while ABC’s first emphasis is on Asia, it is envisioned that the program articulated by the ABC
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science team will become a template for other regions of the world including Africa, America and 

Europe. A primary focus of the project over the short-term is to set up regional aerosol-chemistryclimate observatories. The major goal of these observatories is to estimate the aerosol radiative 

forcing and to relate the forcing to anthropogenic emissions from the region. The observatory 

system includes 10 new observatories in the Indo-Asia-Pacific region, half of which are being 

funded by NOAA and the other half by the governments of China, India, Japan, and other 

associated countries. Currently, three sites are coming online with sites in the Republic of the 

Maldives operational as of October 2004. When these new observatories are combined with three 

alr eady existing observatories in the region, adequate coverage will exist to characterize the 

aerosol radiative forcing of the South and East Asian region. 

The major scientific objectives of the ABC observatories are to: (1) establish continuous chemical 

and microphysical aerosol measurements at key locations in the Indo-Asian-Pacific region with a 

particular emphasis on black carbon, organics and cloud condensation nuclei; 

(2) use regional scale source-receptor models in conjunction with the data from observatories and 

validated satellites to identify the relative contribution of the various Asian regions to the observed 

aerosol loading; (3) determine direct short-wave and long-wave aerosol radiative forcing at the 

surface and top of the atmosphere based on aerosol data in conjunction with comprehensive in situ 

and remote radiometric measurements; and (4) relate the aerosol forcing to regional sources of 

aerosol emissions.

8. Conclusions

GCOS, in consultation with its partners, has developed an implementation plan that, if fully 

implemented, will provide most of the observations of the Essential Climate Variables (ECV) 

listed in Table 1. That plan is in response to the GCOS Second Adequacy Report and has 

considered existing global, regional and national plans, programs and initiatives. The plan was 

developed in consultation with a broad and representative range of scientists and data users, 

including an open review of the implementation plan. There was close collaboration with the ad 

hoc Group on Earth Observations in developing their respective implementation plan. The plan 

identifies implementation priorities, resource requirements and funding options, and includes 

indicators for measuring progress in implementation. 

The goal of the GCOS Implementation Plan is to specify the actions required to implement a 

comprehensive observing system for the ECVs that would, if fully implemented provide for: 

• Global coverage. 

• Free and unrestricted exchange and availability of observations of the ECV 

required for global-scale climate monitoring in support of the UNFCCC. 

• The availability of integrated global climate-quality products. 

• Improvements to and maintenance of the global in situ surface and airborne 

networks and satellites required to sustain these products, including system 
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improvements and capacity building in developing countries, especially in the least 

developed countries and small island developing states. 

• Internationally accepted standards for data and products especially in the terrestrial 

domain and adherence to the GCOS Climate Monitoring Principles. 

• Characterization of the state of the global climate system and its variability. 

• Monitoring of the forcing of the climate system, including both natural and 

anthropogenic contributions. 

• Support for the attribution of the causes of climate change. 

• Support for the prediction of global climate change. 

• Projecting global climate change information down to regional and local scales. 

• Characterizing extreme events important in impact assessment and adaptation, and 

to the assessment of risk and vulnerability. 

As the U.S. plan for climate observations moves forward, it should strive to build on the GCOS 

Implementation plan by addressing the following elements over the near-term (2-4 years); midterm (4-7 years), and long-term (7-10 years), which are in line with goals of the CCSP Strategic 

Plan. 

Maintenance and Standards: A high priority is to maintain and extend the records of key climate 

variables such as global carbon dioxide, ozone, temperature, and othe r essential climate variables 

now being monitored by current systems. The climate quality of these records must be assured by 

adherence to the GCOS climate monitoring principles, as extended by the CCSP Strategic Plan to 

cover satellite systems. 

Modeling and Integration: Continued development and improvement in climate analyses and 

periodic reanalyses is required for integration of climate observations. Continued development of 

ensemble forecasting for climate is needed for applying and evaluating observations, and for better 

definition of requirements for future observations. 

The following address each of the nine challenge themes identified in Table 2. In agreement with 

priorities of the CCSP Strategic Plan, near-term (2-4 year) enhanced observations and research are 

recommended for the first four themes, while enhancements to address the last four are 

recommended for phase-in over the latter part of the 10 year planned period. A detailed phase-in 

plan is needed that provides efficient integrated implementation to address all climate change 

challenge themes within realistic budget constraints, taking advantage where possible of 

governmental and non-governmental partnerships as discussed in section 6. 

Near-term (2-4 years):

Land/Ecosystems/Human Dimensions: Improve monitoring, measuring, and mapping of land 

use and land cover, and the management of these data; Determine cycling of nutrients such as 
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nitrogen and how these nutrients interact with the carbon cycle; launch a follow-on Landsat 

satellite at the earliest possible date, and continue the Landsat long-term acquisition plan. 

Polar/Feedback: Enhance capacity to observe land and sea ice parameters including ice 

thickness; develop continuous high-resolution altimetry over the ice sheets, and SAR capability to 

monitor glacial advance/decline; improve resolution of global gravity measurements; integrate 

modeling of global climate and glaciers/ice sheets. 

Aerosol: Reduce uncertainties in the changing aerosol radiative forcing of climate. This requires 

reduced uncertainty in the sources and sinks of aerosols and their precursors, in aerosol solar 

absorption, and in aerosol effects on cloud radiative fluxes and precipitation. Direct observations 

of aerosol physical and chemical properties and their interaction with clouds and precipitation are 

urgently needed to estimate the aerosol forcing directly from observations and to improve model 

treatments of aerosol forcing. 

Water: Planned satellite measurements and focused field studies to better characterize water 

vapor in the climate-critical area of the tropical tropopause (the boundary between the troposphere 

and the stratosphere) 

Carbon: Determine North American and oceanic carbon sources and sinks; the impact of land-use 

change and resource management practices on carbon sources and sinks; secure the measurements 

needed for the North American Carbon Program (NACP); enhance the ocean carbon observing 

network. 

Mid-Term (4-7 years):

Water: Improve accuracy and global diurnal sampling of precipitation and water vapor to identify 

trends in the intensity of the water cycle; improved global/regional ocean and terrestrial observing 

systems and data exchange; improved technology (satellites and in situ , including suborbital, 

surface, and sub-surface) to measure soil moisture and evapotranspiration; improved observations 

and modeling of water vapor-cloud-climate-radiation feedback processes; closure of terrestrial 

hydrological budgets; impacts of climate change on the global/regional water cycle; and studies 

related to physical/biological and socioeconomic processes to facilitate efficient water resources 

management. 

Radiation Budget: Provide for continuity of solar and Earth-emitted radiation budget 

observations at the top-of-atmosphere and surface, to continue the satellite record that began with 

Nimbus 7 and continues with SORCE and CERES, and maintain the related network of surface 

stations such as SURFRAD, Baseline Surface RadiationNetwork (BSRN), SURFX, and 

DOE/Atmospheric Radiation Measurement (ARM) sites. Supplemental radiation flux observations 

with coordinated observations of detailed wavelength spectra of solar and Earth-emitted radiation, 

are required to better identify mechanisms leading to changes in solar forcing and cloud-radiation 

feedbacks. 

Long-term (7-10 years):
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Temperature: Reducing uncertainties in the evaluation of temperature trends will require: (1) 

implementing an improved climate monitoring system designed to ensure the continuity and 

quality of critically needed measurements of temperature, and concentrations of aerosols and trace 

gases: and (2) making raw and processed atmospheric measurements accessible in a form that 

enables a number of different groups to replicate and experiment with the processing of the more 

widely disseminated data sets such as the MSU tropospheric temperature record. A number of 

possible research strategies for improving the understanding of uncertainties inherent in the 

various measurement systems and the relationship between surface and upper air temperature 

trends are actively being pursued by the CCSP and the international community, and these 

activities need to continue. For example, effective use of independent atmospheric sounding 

systems (MSU, IR, and RO) will produce atmospheric temperature and water vapor fields more 

accurate and reliable than any one sounding system by itself. 

Paleoclimate: Enhance and where possible regularly update paleoclimate observations and data 

management systems to generate a comprehensive set of variables needed for climate change 

research; enhance tree ring, coral and ocean core records. Gaps in paleoclimate observations can 

be categorized in three areas dealing with: (1) physical observations, (2) data management, and (3) 

scientific stewardship. Regarding actual physical observations, the following three areas represent 

the greatest gaps for paleoclimate observations: (1) Collect and analyze 500-2000 year long coral 

records to reproduce temperature and salinity in the tropical oceans; (2) Collect and analyze high 

sedimentation rate deep sea cores; and (3) Produce marine geochemical proxy records of 

temperature trends for the past 2,000 years using corals, mollusks, and marine sediments from 

around the globe. 

Earth Information System 

The integration of a widely diverse system of systems that provides climate quality data is a 

central need. This requires the coordination of climate measurements from across domains in a 

way that provides for seamless access to the data, and appropriate tools for analysis and decision 

support. This coordinated system must be designed to continuously monitor the vital signs of the 

planet, and to provide tools needed to know what is going on in the climate system, to provide for 

full and open access to the data, to support the identification of the forcings and feedbacks, and to 

relate these to the decisions being made by the diverse community of users. The observations must 

be linked together in a synergistic manner, to enable the collection of individual observations to 

produce results than would not have been possible by use of the separate observations by 

themselves. This climate portion of an Earth Information System should establish benchmarks, 

provide for quality control and assurance, and support a seamless continuum of climate prediction 

products on multiple time scales. 

Because of the multiple time scales involved in climate variability and climate change, an area 

requiring future development is the ability to not only track climate anomalies but also to attribute 

them on multiple time scales to:

• External forcings (solar, volcanoes, atmospheric composition) 
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• Internal forcings (e.g., ENSO, SSTs and ocean heat content, soil moisture 

anomalies, state of vegetation, sea ice) 

• Natural variability (essentially unpredictable) 

This will require an operational numerical experimentation program running ensembles of Earth 

system models. At present, this activity is carried out in an ad hoc fashion, often not in real time. 

Institutions such as the NOAA’s Climate Prediction Center, the European Centre for Medium 

range Weather Forecasts, and the International Research Institute for climate prediction, as well as 

many other national meteorological or climate centers, may perform limited experimentation in 

near real time as part of the process of issuing monthly forecasts, or retrospectively to understand 

major anomalies. However, models now appear to have improved sufficiently that results are 

becoming more definitive; such attribution examples include the Sub-Sahara African drought 

beginning in the 1960s and the “Dust Bowl” era in North America in the 1930s. 

Climate observations need to be taken in ways that satisfy the climate monitoring principles and 

ensure long-term continuity and ability to discern small but persistent signals. The health of the 

monitoring system must be tracked and resources identified to fix problems. Satellite observations 

must be calibrated and validated, with orbital decay and drift effects fully dealt with, and adequate 

overlap to ensure continuity. Reanalysis of the records must be institutionalized along with 

continual assessment of impacts of new observing and analysis systems. Such an end-to-end Earth 

information system will be key to the success of the U.S. effort in supporting the GEO over the 

next 10 years. 
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APPENDIX 1 ESSENTIAL CLIMATE VARIABLES

FROM THE GCOS 2nd ADEQUACY REPORT

CROSSWALKED AGAINST THE 9 IWGEO THEMES

IWGEO THEME Weat

her

Disast

ers

Ocean Clim Agric Healt

h

Eco Water Energ

y

Aerosol Properties X X X X X X X X

Air Pressure X X X X X

Air Temperature X X X X X X X X X

Albedo X X X X X X

Biomass X X X

Carbon X X X X X X

CFCs X

CH4 X X

Cloud Properties X X X

CO2 X X X

CO2 Partial 

Pressure X X X X X

Earth Radiation 

Budget (incl. solar 

irradiances) 

X X X X X X X X X

Fire Disturbance X X X X X X X

Fraction of 

Absorbed 

Photosynthetically 

Active Radiation 

(FAPAR) 

X X X X

Glaciers and Ice 

Caps X X X X X

Ground Water X X X X X X X

Lake Levels X X X X X X X

Land Cover (incl. 

vegetation type) X X X X

Leaf Area Index 

(LAI) X X X
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Nutrients X X X X X X

Ocean Color (for 

biological activity) X X X X

Ocean Sub-Surface 

Temperature X X X X X

Ocean Tracers X X X

Other long lived 

GHGs (N2O, CFCs, 

HCFCs, SF6 & 

PFCs) 

X X X X X X

Ozone X X X X X X X

Permafrost and 

Seasonally Frozen 

Ground 

X X X X

Phytoplankton X X X

Precipitation X X X X X X X X X

River Discharge X X X X X X X X X

Sea Ice X X X X X

Sea Level X X X X X

Sea State X X X X X

Sea Surface 

Temperature X X X X X X

Sea-Surface Salinity X X X X

Snow Cover and 

snow water 

equivalent 

X X X X X X X X

Sub-Surface Current X X X

Sub-Surface Salinity X X X

Surface Current X X X X

Surface Radiation 

Budget X X X X X X

Upper air 

temperature (incl. 

MSU radiances) 

X X X X X

Water Use X X X X X X X
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Water Vapor 

(Surface) X X X X X

Water Vapor (Upper 

Air) X X X X X

Wind Speed & 

Direction (Surface) X X X X X X X X
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APPENDIX 2 REFERENCES

CCOIIG, 2003: An Ocean Implementation Plan for the U.S. Carbon Cycle Science Program 

[Doney, S (ed.)]. Carbon Cycle Ocean Interim Implementation Group, University Corporation for 

Atmospheric Research, Washington, DC, USA (manuscript). 

CCSP, 2003: Strategic Plan for the U.S. Climate Change Science Program [J. Mahoney (ed.)]. 

Climate Change Science Program, University Corporation for Atmospheric Research, 

Washington, DC, USA, 69 pp. 

CCWG, 1999: A U.S. Carbon Cycle Science Plan [Sarmiento, J.L. and S.C. Wofsy (eds.)]. Carbon 

and Climate Working Group, University Corporation for Atmospheric Research, Washington, DC, 

USA, 202 pp. 

EHP, 2001: Environmental Health Perspectives: Human Health Consequences of Climate 

Variability and Change for the United States [Bernard, S.M., M.G. McGeehin, and J.A. Patz 

(eds.)]. EHP Supplement 109(2), Public Health Service, U.S. Department of Health and Human 

Services, Washington, DC, USA, 64 pp. 

FAO, 2002: Terrestrial Carbon Observation: The Rio de Janeiro Recommendations for Terrestrial 

and Atmospheric Measurements [Cihlar, J., S. Denning, F. Ahern, F. Bretherton, J. Chen, C. 

Dobson, C. Gerbig, R. Gibson, R. Gommes, T. Gower, K. Hibbard, T. Igarashi, R. Olson, C. 

Potter, M. Raupach, S. Running, J.Townshend, D. Wickland, and Y. Yasuoka (eds.)]. 

ESMF, 2004: Grand Challenges in Earth System Modeling, Computing in Science and 

Engineering, Vol 6, #1, pp. 13-51, published by IEEE Computer Society, Jan-Feb 2004. 

FAO Environment and Natural Resources Series No. 2.United Nations Food and Agriculture 

Organization, Rome, Italy, 42 pp. 

Global Carbon Project, 2003: Science Framework. Earth System Science Partnership (IGBP, 

IHDP, WCRP, Diversitas). Global Carbon Project No. 1, Canberra, Australia (in press). 

GCOS-U.S. , 2001: The United States Detailed Report on Systematic Observations for Climate: 

United States Global Climate Observing System (U.S. -GCOS) Program, [H. Diamond ed.]. DOC 

Pub, 138 pp. 

GCOS, 2003: The Second Report on the Adequacy of the Global Observing Systems for Climate 

in Support of the UNFCCC. WMO-IOC-UNEP-ICS, GCOS-82, Technical Document No. 1143, 

World Meteorological Organization, Geneva, Switzerland, 85 pp. 

GOOS, 2002: A Global Ocean Carbon Observation System - A Background Report [Doney, 

S. and M. Hood (eds.)]. Global Ocean Observing System Report No. 118, UNESCO 

Intergovernmental Oceanographic Commission, IOC/INF-1173, 55 pp. 
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