Modeling of dynamic thickening due to past climate change in East Antarctica ice sheet

Wednesday, 17 December 2014
Weili Wang, H Jay Zwally and Jun Li, NASA Goddard SFC, Greenbelt, MD, United States
The satellite observations from the ERS (1999-2008) and ICESat (2003-2008) show a net mass gain from snow accumulation exceeded losses of ice discharge in East Antarctica ice sheet. The observed thickening rate inland in East Antarctica is 2 cm/a. To investigate the dynamic thickening rate, we apply the 3D AIF (Anisotropic Ice Flow) model to the Antarctica ice sheet for a series of the sensitivity experiments with the changes in climate forcing (surface mass balance and temperature). The modeled thickening rate near Vostok for the present time is consistent with the observations from ICESat and ERS data. The model results indicate that the East Antarctica ice sheet has been growing due to increased snowfall after the last ice age, and that the observed net mass gain is mainly caused by persistent dynamic thickening (excess of long-term accumulation relative to ice flow), and not by contemporaneous increases in snowfall.