PROGRAM TITLE: Landsat Program ACTIVITY STREAMS: Observations and Data Management, Process Studies, Integrative Modeling and Prediction, Assessment SCIENCE ELEMENT:Biogeochemical dynamics Ecological systems and dynamics Earth system history Human interactions Global observing systems Data and information management NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SCIENTIFIC MERIT: The Landsat Program is assisting a broad range of global change research activities by providing data suitable for long term studies of land cover and biogeochemical processes. The instruments on the Landsat series of satellites, the Multispectral Scanner System (MSS) and the Thematic Mapper (TM), have been collecting data longer than any other sensing devices designed to monitor earth resources. The spatial resolution and spectral sensitivity of the MSS and TM provide useful data on land processes and are ideal for extrapolating insights obtained from local process studies to regional and global scales. As such, Landsat data are used widely in natural science and social science research directed, generally, toward phenomena that affect the physical and cultural landscape and, specifically, toward significant issues in global change research. The Landsat Program is making data available to the global change community by: 1) improving accessibility of data in the Landsat archive for retrospective studies; 2) augmenting the existing archive by purchasing data for specific national and international global change research projects such as the IGBP and research directed toward specific topics such as tropical forest deforestation, desertification, and long term ecological research; and 3) assuring the continuity of Landsat and/or Landsat-like data by participating in the procurement, operation, and management of a new Landsat satellite, Landsat 7, and by participating in the development of an advanced land remote sensing system. In virtually all global change studies that use Landsat data, the characteristics of the data set of greatest value are the ability to extract land cover information and the length of the data record. Land cover is a manifestation of biophysical and/or cultural process and can be used to measure the areal extent of the process. The historical record of Landsat data provides documentable evidence on change in the areal extent of a process and rate of process change. Because of these characteristics, Landsat data are a key link between local process studies and understanding the distribution and impact of phenomena at a global level. These data have been used, and will continue to be applied, to study topics as diverse as nutrient cycling (expressed in leaf canopy chemistry,) and the effects of urbanization on agricultural communities. Landsat data are fundamental in modeling phenomena that affect global environments such as the distribution of snow and ice (hence, climate change) and atmospheric phenomena when those phenomena are influenced by ground processes. STAKEHOLDERS: The Landsat Program cuts across all the federal departments and agencies involved with CEES. Landsat data are fundamental in their basic and applied research programs that address global change issues. POLICY RELEVANCE: Primary Ð Land use change, human interactions, biogeochemical dynamics, ecosystem science Secondary Ð Climate change PROGRAM CONTACT:Stanley R. Schneider Code YD NASA Headquarters Washington, DC 20024 202-358-0255