HR: 1340h
AN: C33C-0357    [Abstracts]
TI: Precise Elevation Profiles Across Antarctic Megadunes
AU: * Suchdeo, V P
EM: vsuchdeo@icesat2.gsfc.nasa.gov
AF: NVI, Inc., Oceans and Ice Branch, Laboratory for Hydrospheric Processes, NASA Goddard Space Flight, Code 971, Building 33, Room B209B, Greenbelt, MD 20771 United States
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
AU: Scambos, T A
EM: teds@nsidc.org
AF: National Snow and Ice Data Center, CIRES, University of Colorado, Campus Box 449, Boulder, CO 80309 United States
AU: Fahnestock, M A
EM: mark.fahnestock@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824 United States
AU: Albert, M R
EM: Mary.R.Albert@erdc.usace.army.mil
AF: USACE Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH 03755 United States
AU: Bauer, R
EM: bauerr@nsidc.org
AF: National Snow and Ice Data Center, CIRES, University of Colorado, Campus Box 449, Boulder, CO 80309 United States
AB: Covering more than 500,000 square kilometers of Antarctica, megadune features are related to persistent, down slope winds and have a subtle but characteristic morphology that is best defined by precise elevation data. In this paper, we will discuss ICESat precision laser altimetry data that details some of these features near an NSF-OPP funded research site occupied during the 2002-2003 and 2003-2004 field seasons. Work there to-date shows megadunes having 1) amplitudes from about 2 to 8 meters, 2) wavelengths of approximately 2 to 6 kilometers, 3) crest lengths of up to 100 kilometers, 4) a steeper and rougher upwind face, and 5) a smoother and longer backslope. See other talks in this session (e.g. Scambos et al.,) for additional details of their characteristics and formation. In this harsh environment, satellite altimetry is an excellent way to gather the elevation data needed to define these features. The ICESat mission acquires elevation data with a measurement spacing of about 172 m along its orbital track and can repeat a track to within approximately 50 meters. When skies are clear, ICESat measures laser spot elevations with 2 to 3 centimeter precision over these slowly-changing, undulating ice sheet features. Clouds, although rare in this area, can degrade the elevation data precision by more than a meter. Data obtained during ICESat's first four operational periods clearly documents the megadune and other ice sheet features in the region and enables the impact of clouds and the overall precision of this data to be quantified. ICESat data calibration and validation is being aided by high-precision GPS data acquired on sled traverses in the field area. The combination of ICESat data with a recently completed Antarctic MODIS mosaic will allow additional aspects of these features to be discussed.
UR: http://icesat.gsfc.nasa.gov/
DE: 3349 Polar meteorology
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting