MASS BALANCE OF ANTARCTIC ICE SHEET FROM 2003 TO 2008: A SYSTEMATICALLY IMPROVED NEW ESTIMATION

Abstract

There exist several results of mass balance of the Antarctic Ice Sheet (AIS) estimated based the laser altimetry ICESat, especially for some with a significant difference. In this study, we attempt to use the ICESat data to re-estimate the mass balance of the AIS over 2003-2008 by making several systematic improvements in data processing and model construction. We applied all corrections to the ICESat data including the re-estimation of the ICB. A three-step model was used in different area for calculating elevation changes of the Antarctica ice sheet. The elevation change rate was compared with other results generated from Global Position System (GPS), stakes, Airborne Terrain Mapper (ATM) and CHINRE data. These verification data proved a good agreement between each other considering the uncertainty involved. We also corrected the component in the elevation change rates that do not contribute to the mass loss such as the global isostatic correction and firn compaction. The corrected elevation change result was converted to the mass change using a surface density model.