PROGRAM TITLE: Mission Operations and Data Analysis (MO&DA) ACTIVITY STREAM: Data and Observations SCIENCE ELEMENT:Climate and Hydrologic Systems Biogeochemical Dynamics Ecological Systems and Dynamics Earth System History Solid Earth Processes Solar Influences Global Observing Systems NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SCIENTIFIC MERIT: The objective of the Mission Operations and Data Analysis program is to acquire, process, and archive long-term data sets produced by spaceborne missions, which are funded by other programs until they are launched. These data relate to issues of global change in atmospheric ozone and trace chemical species, the Earth's radiation budget, aerosols, sea ice, land surface properties, and ocean circulation and biology. SAM-II and SAGE-2 The Stratospheric Aerosol Measurement II (SAM-II) instrument on the Nimbus-7 satellite will conclude its measurements in December, 1993, having collected a 15-year data set on atmospheric aerosols (and stratospheric clouds) in Earth's polar regions. Data from the Stratospheric Aerosol and Gas Experiment II (SAGE-II), on NASA's Earth Radiation Budget Spacecraft (ERBS), continue to provide vertical profiles of aerosols, ozone, nitrogen dioxide, and water vapor over Earth's tropical and mid latitude regions, as they have since ERBS launch in 1984. ERBS The Earth Radiation Budget Experiment (ERBE), is composed of three identical instrument packages flying on NOAA-9, NOAA-10, and NASA's ERBS. These instruments provide data illuminating the temporal and spatial variations in the Earth's radiation budget, which drive the Earth's climate, as they have since the launch of ERBS in 1984. Data from the Earth Radiation Budget (ERB) instrument on Nimbus-7, and from the ERBE instruments, provide the only continuous data set on total solar irradiance ("solar constant") and its temporal variations stretching from 1978 to the present. NOAA 9 and 10 operations continue to support ERB non- scanner measurements. ERB measurements onboard Nimbus 7 will conclude in December 1993 due to the deterioration of the satellite's orbital geometry. ASF SAR data transmitted from ESA's ERS-1 spacecraft is acquired, processed, and archived by NASA's Alaska SAR (Synthetic Aperture Radar) Facility (ASF), based at the Geophysical Institute, University of Alaska, Fairbanks. ASF is doing the same with SAR data from Japan's ERS, and is planning to support ESA's ERS-2, and Canada's RadarSat spacecraft when they become operational. These data provide important information on the properties and dynamics of sea ice and other land and sea processes in the polar regions. SIR-C The Spaceborne Imaging Radar-C (SIR-C) builds upon the heritage of spaceborne synthetic aperture radar (SAR) missions Seasat SAR (1978), SIR-A (1981) and SIR-B (1984) in the use of SAR technology to study earth science. Because of SAR's ability to image the earth through cloud cover, sensitivity to surface roughness, soil moisture, and ice-water contrast, it is useful in studies of geological features. canopy morphology, sea ice dynamics, and ocean surface features. SIR-C provides the opportunity to identify the optimum wavelengths, polarizations, and illumination geometries for SAR imagery of the earth. Ocean Color NASA will purchase, from the Orbital Sciences Corporation (OSC), ocean color data to be acquired by the SeaWiFS instrument which will fly on the SeaStar satellite to be launched in July, 1994. SeaWiFS will provide worldwide high-precision, moderate-resolution, multispectral visible observations of ocean radiance, thus building on the experience gained from the Coastal Zone Color Scanner (CZCS) on Nimbus-7. These data should determine the mean and variable bio-optical reflectance characteristics of the upper ocean, leading to an understanding of the primary productivity of the upper oceans and the affected fluxes of carbon dioxide and other trace gases across the air-sea interface. MO&DA will fund the acquisition, processing, and archiving of resulting long- term data sets. STAKEHOLDERS: National and international connections are a natural part of this program. There are ongoing interagency connections with NOAA and international agreements with ESA, Japan, and Canada. International agreements provide that the Alaska SAR Facility will acquire SAR data from satellites flown by ESA (the European Space Agency), Japan, and Canada. SIR-C is a joint mission with a European consortium consisting of the DLR (Germany) and ASI (Italy); the consortium is referred to as X-SAR in reference to the X-band radar sensor they are contributing to the SIR-C/X-SAR experiment. Nationally, the SIR-C Science Team includes members representing the USGS and USDA. Demand for SeaWiFS ocean color data is expected to be led by the Joint Global Ocean Flux Study (JGOFS), part of a core program of the International Geosphere-Biosphere Program (IGBP). Other multinational studies that will rely on ocean color data include the World Ocean Circulation Experiment (WOCE) and the International Global Atmospheric Chemistry (IGAC) program. POLICY RELEVANCE: Climate Change and Natural Variability Biodiversity Forests and Deforestation Desertification PROGRAM CONTACT:Mr. Stanley Schneider Chief, Mission Operations and Data Analysis Branch NASA Headquarters, Code YD Washington, DC 20546 202-358-0255 sschneider@mtpe.hq.nasa.gov