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APPENDIX B

    Areas of Global Change Research. NASA research efforts in global change involve space-based studies of the Earth as an integrated system, including research and satellite programs studying atmospheric chemistry and ozone; ocean surface winds and ocean biological productivity; tropical precipitation and the global hydrological cycle; the global carbon cycle and land surface vegetation and ecosystems; and solid Earth geophysics. The space-based activity complements ongoing ground-based research programs in the observation, understanding, and modeling of radiation, climate dynamics, and hydrology and water resources; ecosystem dynamics and biogeochemical cycles; atmospheric chemistry; solid Earth science; and the processing, archiving, retrieval, dissemination, and use of global change data. The focus is Earth system science, which involves interdisciplinary research and coupled modeling. Development of algorithms for retrieval of the information content of space-based, remotely-sensed observations is carried out as part of the flight mission.

    FY 2000 Program Highlights. The overall goal of NASA’s Earth Science Enterprise (ESE) is to understand the Earth system and the effects of natural and human-induced changes on the global environment. To preserve and improve the Earth’s environment for future generations, policies and decisions worldwide should have the strongest possible scientific basis. The vantage point of space provides information that is obtainable in no other way about the Earth’s land, atmosphere, ice, oceans, and biota, as well as the impact of humans on the Earth system.

    The science and observations of ESE are becoming increasingly important as nations work to meet the demand for economic progress by a growing global population. In addition, remote sensing has the potential to improve dramatically crop and forest yield predictions, seasonal and interannual climate forecasts, urban planning, mineral exploration, and many other activities of socioeconomic importance. In concert with the global change research community, the ESE is utilizing the vantage point of space to lead the development of knowledge required to support the complex national and international policy decisions that lie ahead.

    As was the case last year, this edition of Our Changing Planet divides the ESE budget into two main components: 1) scientific research, and 2) the budget associated with satellite, aircraft, and balloon measurements, operations, and data processing and distribution (including mission costs such as launch, flight, instrument and technology development, fabrication assembly, integration, and testing, as well as mission operation support).

    Scientific Research. The scientific research component of the ESE budget is supported by an integrated science plan that relates research plans to space observations, and fully integrates the Earth Observing System (EOS) and non-EOS science. EOS is a program of multiple spacecraft and interdisciplinary science investigations, designed to provide a 15-year data set of key parameters needed in order to understand global climate change. The major themes of NASA’s ESE Science Research Plan are consistent with the newly refined USGCRP Program Elements for FY 2000.

    Against the backdrop of the overall ESE effort to better understand the state and health of the Earth’s life-support systems, NASA’s FY 2000 research will target specific research issues important to national and international environmental and economic security. Through increases in Interdisciplinary Research and Analysis funding and targeted augmentations in the Vegetation Canopy Lidar (VCL) and Sensor Intercomparison and Merger for Biological and Interdisciplinary Ocean Studies (SIMBIOS) components of the Mission Analysis Program, NASA will participate in the new interagency Carbon Cycle Science Program. New research will focus on exploiting data from new satellites (i.e., EOS AM-1, Landsat 7, VCL, EO-1) to document the role of land cover change, ecosystem disturbances, and interannual variability in terrestrial and marine ecosystem productivity in regional and global carbon dynamics. Another important priority is to provide an accurate assessment of the extent and health of the world’s forests, grasslands, and agricultural resources.

    In a time of rapid, and often unrecorded, land-use change, observations from space are the only source of objective information on the human use of land. A closely related priority is to improve understanding and prediction of seasonal to interannual climate variation. Reducing uncertainties in climate predictions out to a season or a year in advance can help improve dramatically the efficiency of water use for agriculture and hydropower, as well as improve contingency planning for energy demand and in other economic sectors.

    In addition, the ESE natural hazards research priority emphasizes the use of remote-sensing observations for the characterization and mitigation of drought and flood impacts. There is increasing evidence that predictions of extreme weather events can be improved by understanding their links to interannual climate phenomena, such as the El Niño events. The ESE Science Plan also calls for special attention to measuring and modeling the relative influence of forcing factors in long-term climate change, including clouds, aerosols, and greenhouse gases, in order to improve the understanding and prediction of climate on time scales of decades to centuries. A continuing priority area for ESE is to understand the causes and consequences of changes in atmospheric ozone. Research to resolve questions related to stratospheric ozone depletion continues to make great progress, and increased emphasis is now being focused on the changing composition of the lower atmosphere, which is especially sensitive to the unprecedented growth of pollutant emissions in East Asia and other rapidly developing regions.

    Satellite, Aircraft, and Balloon Measurements, Operations and Data Processing and Distribution. The Earth Observing System is a program of multiple spacecraft (the AM, PM, and CHEM series, Landsat-7, and others) and interdisciplinary science investigations to provide a 15-year data set of key parameters needed to gain a fuller understanding of global climate change. The first EOS satellite launches begin in 1999, with Landsat-7, QuikSCAT, and AM-1.

    Preceding EOS are a number of individual satellite and Shuttle-based missions which are helping to reveal the basic processes of atmospheric chemistry (Upper Atmosphere Research Satellite-UARS/1991), ozone distribution and depletion (Total Ozone Mapping Spectrometer-TOMS/1978, 1991, 1996, and 2000), ocean topography and circulation (TOPEX/Poseidon/1992), ocean winds (NASA Scatterometer-NSCAT/1996), and global tropical precipitation (Tropical Rainfall Measuring Mission-TRMM/1997), among others. These provide the scientific and technological foundation on which EOS builds. TRMM was launched in November 1997, and is now fully operational. It will provide important data on precipitation in the tropics that will help better understand the global hydrological cycle.

    Continuing the deployment of EOS, FY 2000 will see the launch of the Active Cavity Radiometer Irradiance Monitor (ACRIM) mission, the SeaWinds scatterometer on Japan’s ADEOS II mission, and the US/France Jason-1 — a follow-on to the highly successful TOPEX/Poseidon mission. In addition, we will launch the New Millennium Program Earth Observer-1 technology demonstration mission, designed to make future Landsat-type missions possible at vastly reduced size and cost. The New Millennium Program (NMP) provides for the infusion of innovative new technologies into ESE, with an initial focus on the EOS follow-on missions, and will emphasize fast-track development and low-cost demonstration missions. These technologies, which will lead to the development of smaller and lighter-weight instruments, will reduce annual program expenditures in the post-FY 2000 time frame.

    Complementing EOS will be a series of small, rapid-development Earth System Science Pathfinder (ESSP) missions to study emerging science questions and make innovative measurements in parallel with the systematic, long-term measurements begun with EOS. ESSP will feature low life-cycle costs, peer-reviewed science, and missions based on best science value. The first two ESSP missions-Vegetation Canopy Lidar (VCL) and Gravity Recovery and Climate Experiment (GRACE)-were selected and are scheduled for launch in 2000 and 2001, respectively. And late in the fiscal year, ESE will fly the Shuttle Radar Topography Mission to use interferometric synthetic aperature radar to produce the first widely available, nearly global, digital-elevation model.

    ESE has adopted an evolutionary approach to fulfilling its mission and goals. Future missions needed to achieve continuity for systematic measurements, together with those in the exploratory mode of ESSP, will be implemented according to the "better/faster/cheaper" paradigm. ESE will use commercially available spacecraft in a "catalog" procurement mode to reduce the cost and development time required to prepare a mission for launch. Meanwhile, ESE will invest upfront in instrument technology development, and base its mission selection on both scientific need and technology readiness. In 1998, ESE developed a notional multi-mission scenario for the years 2003-2010, and in 1999 it will be reviewed by the National Academy of Sciences and discussed with prospective interagency and international partners. In FY 2000 the first mission solicitation(s) for EOS follow-on missions will be prepared.

    Related Research. All NASA global change research is included in the USGCRP program.

    Mapping of Budget Request to Appropriations Legislation. In the Departments of Veterans Affairs and Housing and Urban Development, and Independent Agencies Appropriations Bill, National Aeronautics and Space Administration USGCRP activities are funded under the NASA section of Title IIIÐIndependent Agencies, as part of the Science, Aeronautics, and Technology account. Within this account, Appropriations Committee reports specify funding for the Earth Science program.