HR: 1330h
AN: C32A-0443    [PDF]
TI: Analysis of Ice Elevations along ICESat Repeat Tracks over Law Dome ice cap, East Antarctica
AU: * Li, J
EM: lijun@icesat2.gsfc.nasa.gov
AF: Raytheon ITSS,, Building 33, Code 971, NASA/Goddard Space Flight Center,, Greenbelt, MD 20771 United States
AU: Zwally, H J
EM: zwally@icesat2.gsfc.nasa.gov
AF: Oceans and Ice Branch,, Building 33, Code 971, NASA/Goddard Space Flight Center,, Greenbelt, MD 20771 United States
AU: Wang, W
EM: weili@icesat2.gsfc.nasa.gov
AF: Raytheon ITSS,, Building 33, Code 971, NASA/Goddard Space Flight Center,, Greenbelt, MD 20771 United States
AU: Shuman, C A
EM: christopher.shuman@gsfc.nasa.gov
AF: Oceans and Ice Branch,, Building 33, Code 971, NASA/Goddard Space Flight Center,, Greenbelt, MD 20771 United States
AB: The Law Dome ice cap adjoining the main East Antarctic ice sheet in Wilkes Land between longitudes 110,aE and 116,aE is about 200 km in diameter with a maximum surface elevation of 1389 m. Satellite radar altimetry results (ERS1-2) and ice flow modeling by using annual layer data derived from the deep ice cores show that the ice cap is currently close to steady state. Law Dome is characterized by a complete range of ice formation zones with extraordinarily large accumulation gradient from west to east from negative values in the ablation zone to about 4 m a-1 net accumulation in the dry snow zone. As an analogue of the main Antarctic ice sheet, Law Dome is an ideal location to examine ICESat capabilities and data quality and to perform detailed studies of seasonal and interannual changes in surface elevations. So far, data from the three 8-day repeat cycles crossing over the ice cap in February-March, 2003 are analyzed. The average separation between the repeat tracks and a reference track varies from 354 to 930 m. To inter-compare the elevations from the three profiles, the elevations are corrected for the cross-track slope estimated from the three profiles to obtain the respective elevations along the reference track. Comparisons of the derived elevations for different cycles show the high accuracy of the ICESat data with standard deviation of 30 cm for the entire crossing range and 6 cm for the lower slope region near the summit. The preliminary data also reveal systematic changes in surface roughness, with higher values at low elevations due to melting and wind erosion features, and minimum values near the summit that well agree with ground observations.
DE: 1640 Remote sensing
DE: 1827 Glaciology (1863)
DE: 9310 Antarctica
SC: Cryosphere [C]
MN: 2003 Fall Meeting