PROGRAM TITLE: Upper Atmosphere Research Satellite (UARS) ACTIVITY STREAM: Data and Observations SCIENCE ELEMENT:Climate and Hydrologic Systems Global Observing Systems NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SCIENTIFIC MERIT: The UARS program consists of a single, dedicated, fully-instrumented satellite and associated ground system designed to obtain the first global-scale data base on the chemistry, dynamics, and energy input to the Earth's upper atmosphere. Specifically, the UARS mission studies energy input and loss in the upper atmosphere, global photochemistry of the upper atmosphere, dynamics of the upper atmosphere, the coupling among these processes, and the coupling between the upper and lower atmosphere. Launched in September, 1991, the UARS payload includes 10 instruments using proven technologies to measure upper atmosphere winds, stratospheric temperatures, solar energy input, and radiative loss. It also monitors the concentrations of a large number of stratospheric and mesospheric chemical species whose atmospheric presence is derived in large part from human activities. UARS continues key observations made by current and planned satellite instruments and will be followed by the EOS mission, which will continue these measurements on a long-term basis. STAKEHOLDERS: Extensive linkages have been put in place with the international and inter-agency scientific community for instrument development and testing, ground data system procurement and installation, data analysis and utilization, and the development of ground-truth and correlative measurement campaigns. The broader scientific community will use UARS data in an ongoing program of international ozone assessments undertaken through the auspices of the United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO). POLICY RELEVANCE: Climate Change and Natural Variability Stratospheric Ozone and UV-B Radiation UARS helps to fulfill NASA's legislative mandate to research and understand the upper atmosphere and its susceptibility to change, caused by natural events or anthropogenic activities. By providing simultaneous, coordinated measurements of atmospheric internal structure and measurements of the external influences acting on the atmosphere, UARS is advancing the understanding and prediction of stratospheric ozone depletion and of climate change. 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