The Greenland cryosphere is undergoing rapid changes, and these are documented by remote sensing from space. In this paper, an inversion scheme is used to derive mass changes from gravity changes observed by GRACE, and to derive the mean annual mass loss for the Greenland Ice Sheet, which is estimated to be 204 Gt/yr for the period 2002-2010. NASA’s laser altimetry satellite ICESat has provided elevation estimates of the ice sheet since January 2003. In order to be able to compare GRACE and ICESat derived results, the ICESat volume change must be converted into a mass change estimate. Therefore, it is necessary to model the densities and compaction of the firn. We find that data from ASIRAS show great potential for validating the glaciological models used to determine the densities and firn compaction.
Greenland Ice Sheet Changes From Space Using Laser, Radar and Gravity, 2010