PROGRAM TITLE: Earth Observing System (EOS) ACTIVITY STREAMS: Observations, Process Studies, Integrative Modeling and Prediction, Assessment SCIENCE ELEMENTS:Climate and Hydrological Systems Biogeochemical Dynamics Ecological Systems and Dynamics Solid Earth Processes Solar Influences Data and Information Management NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SCIENTIFIC MERIT: EOS will provide an integrated, comprehensive measurement program for systematic observation of the whole Earth from space that will enable scientists to both monitor global change and study a wide range of processes governing the environment. In particular, EOS will provide observations and focused research on: 1. Water and Energy Cycles -- Cloud formation, dissipation, and radiative properties, which influence response of the atmosphere to greenhouse forcing -- Large-scale hydrology and moisture processes, including precipitation and evaporation 2. Oceans -- Exchange of energy, water, and chemicals between ocean and atmosphere, and between the upper layers of the ocean and deep ocean (includes sea ice deformation of bottom water) -- Sources and sinks of greenhouse gases 3. Chemistry of Troposphere and Lower Stratosphere -- Links to the hydrologic cycle and ecosystems, transformations of greenhouse gases in the atmosphere, and interactions inducing change 4. Land Surface Hydrology and Ecosystem Processes -- Improved estimates of runoff over the land surface and into the oceans -- Sources and sinks of greenhouse gases -- Exchange of moisture and energy between the land surface and atmosphere -- Changes in land cover 5. Glaciers and Polar Ice Sheets -- Predictions of sea level and global water balance 6. Chemistry of the Middle and Upper Stratosphere -- Chemical reactions, solar-atmosphere relations, and sources and sinks of radiatively important gases 7. Solid Earth -- Volcanoes and their role in climate change. EOS research will be accomplished, in part, through the flight of advanced research sensors on polar orbiting platforms and other low-altitude, Earth-orbiting spacecraft. These satellites will provide global coverage to observe all land, oceans and atmosphere. This observing system will be operated for at least 15 years beginning in 1998. EOS is based on a rich scientific heritage; each instrument type baselined for EOS has flown, or will fly, prior to EOS launch, as a satellite, Space Shuttle, aircraft, or balloon payload. All the data will be reduced, analyzed, and made readily available to the EOS research community and others through the EOS Data and Information System (EOSDIS). Scientific guidance of the development and deployment of EOS measurement capabilities is provided by selected interdisciplinary research teams and other scientific participants affiliated with and supporting each of the EOS instruments. The scientists funded under the EOS are developing new models and extending the capabilities of those that now exist, as well as analyzing current data that contribute to global change research. Their activities include developing conceptual, diagnostic, and predictive models along with data assimilation techniques for incorporating satellite and other data into such models. Current benefits from EOS-supported research include the enhanced production and availability of key geophysical data sets from past and ongoing satellite observations and new modeling results. EOS is the centerpiece of the Global Change Research Program (GCRP). As such, the EOS mission embraces the overall goal and addresses each of the three scientific objectives of the U.S. GCRP. All of the scientific research elements of EOS have been selected through peer evaluation and have been reviewed by science advisory committees both at NASA and at the National Academy of Sciences. The EOS mission was reviewed and endorsed by the Earth System Sciences Committee. Appropriate agency, interagency, scientific, and international reviews have demonstrated that EOS is both scientifically and technically sound. EOS activities include participation by NOAA, USGS, and DOE in the development and operation of the EOSDIS. The NOAA Polar- Orbit Earth Observation Mission is coordinated with EOS activities, and EOS will provide new instruments with operational potential. NOAA will sample data streams from EOS instruments, and incorporate selected units into their operational meteorological satellite program once they are deemed sufficiently reliable. EOS has been planned and coordinated with the Earth observations programs of the European Space Agency (ESA), Canada, and Japan. A coordinated set of platforms and payloads will be launched, and the resulting data will be fully exchanged. Instruments from ESA, France, Canada, and Japan are slated for flight on NASA EOS platforms. NASA EOS instruments will also fly on Japanese Advanced Earth Observing System (ADEOS) platforms and the joint U.S-Japan Tropical Rainfall Measuring Mission (TRMM). STAKEHOLDERS: Overall activities are guided by recommendations of the interagency Committee on Earth and Environmental Sciences (Working Group on Global Change) , the relevant panels of the National Research Council (e.g., Climate Research Committee of the Board on Atmospheric Sciences and Climate, and the Committee on Global Change), and other committees which work to define the U.S. Global Change Research Program. On the International level, EOS has scientific linkages to projects of the World Climate Research Program (e.g., GPCP, GEWEX, ISCCP, ISLSCP, TOGA, and WOCE) and of the International Geosphere Biosphere Program (e.g., BAHC, GCTE, GLOBEC, IGAC, JGOFS, and LOICZ). The EOS Program also sponsors NASA participation in climate impact assessments by the Intergovernmental Panel on Climate Change. Japan and ESA are developing complementary programs, which together with EOS win make up the International Earth Observing System. POLICY RELEVANCE: Primary: Climate Change Assessment Secondary: Global Warming Biogeochemical cycles (Water, C) Tropospheric greenhouse gases Ecological change and biodiversity Polar ice sheets and sea level Stratospheric ozone and UV-radiation Solid Earth (volcano impacts on) PROGRAM CONTACT:Ghassem Asrar Office of Mission to Planet Earth NASA Headquarters, Code YS Washington, DC 20546 Tel: 202-358-0266 email: G.ASRAR/Omnet email:gasrar@sedsparc.ossa.hq.nasa.gov/Internet