NASA satellites (Figure 13) support an extensive Global Water Cycle science focus area and contribute to high accuracy, stable, sustained observations and associated modeling for terrestrial hydrology and cryosphere studies. Derived geophysical products for terrestrial hydrology and cryosphere are available from the NSIDC’s Distributed Active Archive Center (DAAC). They include: soil moisture and snow water equivalent from AMSR-E; Greenland ice sheet altimetry and global land surface altimetry from ICESat/GLAS; snow cover extent/area from MODIS; surface albedo and temperature from AVHRR Pathfinder. SAR data obtained from a variety of foreign satellites since 1991 are archived at the ASF DAAC. SAR data provide opportunities for change detection, including interferometric SAR (InSAR) studies of glacier and ice sheet surface elevation and dynamics (ice velocity maps), land surface elevation, and soil moisture. GRACE has been used to determine the mass loss from the Greenland ice sheet and from glaciers in southeast Alaska. The surface elevation of the Greenland ice sheet is mapped using ICESat, and the Advanced Spaceborne Thermal Emission and Reflec¬tion Radiometer (ASTER) is used to acquire imagery and topography of the ice sheet.