Mass Balance and Evolution of Supraglacial Hydrology over South-West Greenland

Abstract:

Southwest Greenland experiences one of the highest ablation rates on the ice sheet. Atmospherically controlled surface melt on the cluster of land-terminating glaciers in this region can be used to quantify how surface mass balance has changed in the recent decades and the state and fate of the melt water generated on the ice surface. Here, we constrain surface mass balance during 1993-present using a melt model, laser altimetry derived elevation changes and ice dynamics using ice surface velocity, over Russell Glacier, Greenland. Our preliminary results using IceBridge laser altimetry show that the Russell Glacier thinned almost three times faster during the warmer periods of 2010-2011 compared to 1993-2010. The surface melt component forms a significant fraction of the thinning rates based on observed surface mass balance rates from the K-Transect nearby.

We use surface melt from the melt model and the partitioned surface melt from laser altimetry to study to how the surface morphology of the supraglacial channels evolve in response to surface lowering and increased surface melt. The overarching goal is to use surface melt, thinning rates and evolving supraglacial channels as proxies of ice sheet mass balance and water budget.