HR: 09:30h
AN: H21I-07 INVITED     [Abstracts]
TI: A Space Lidar Monitoring the Global Water Cycle - NASA's ICESat Mission
AU: * Shuman, C A
EM: Christopher.A.Shuman@nasa.gov
AF: Oceans and Ice Branch, Laboratory for Hydrospheric Processes, NASA Goddard Space Flight Center, Code 971, Room A210, Building 33, Greenbelt, MD 20771 United States
AB: Since it was launched and began operating in early 2003, NASA's Ice, Cloud, and land Elevation Satellite (ICESat) has produced valuable data on aspects of the global water cycle with its two-channel Geoscience Laser Altimeter System (GLAS) instrument. ICESat was specifically designed to provide precision elevation data through time across Greenland and Antarctica between ~86 deg. N-S latitude. This data, accumulated from repeat tracks and crossovers, will enable improved estimates of ice sheet mass balance and any ongoing changes. Because of its potential impact on the altimetry data, a second and complimentary mission goal was to collect data on clouds and aerosols and their distribution around the world. Other aspects of the global hydrologic cycle were also part of the initial mission plan including sea ice, vegetation cover, surface hydrology, and ocean applications. This presentation will highlight results from ICESat's operations in 2003 and 2004. Although technical issues with GLAS have more than halved the planned mission, the precision of the available altimetry data is excellent and glaciologically significant results are being derived. Cloud and aerosol layers are being resolved with unprecedented detail and indicate, for example, that deep convection reaches the tropopause far more frequently than had been previously thought. Sea ice cover and thickness maps are being derived for both Arctic and Antarctic waters. Characteristics of vegetation cover can also be retrieved for a limited range of surface slopes. Surface water results from ICESat include detection of river surface slopes along long sections of river channel or between multiple track crossings of a meandering channel with an accuracy sufficient for detection of stage changes over time, In summary, the precise laser altimetry data from ICESat and GLAS is establishing a valuable global framework. Due to its restricted operations plan, creative use of other earth-observing sensors as well as modeling will be needed to fully utilize the data being acquired by ICESat.
UR: http://icesat.gsfc.nasa.gov/
DE: 4207 Arctic and Antarctic oceanography
DE: 1827 Glaciology (1863)
DE: 1860 Runoff and streamflow
DE: 1863 Snow and ice (1827)
DE: 0305 Aerosols and particles (0345, 4801)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting