Sensitivity of Dynamic Change to Basal Sliding of the Greenland Ice Sheet

This paper presents the results from the modeling experiments of Sea-level Response to Ice Sheet Evolution (SeaRISE) project, a community ice-sheet modeling effort to provide quantitative estimates of ice sheet contributions to sea level rise in the 21st century for 5th IPCC report. In order to study the sensitivity of ice sheet to the changes of sliding at the subglacial interface, the SeaRISE experiments are set to enhance the basal sliding velocity by an amplification factors as 2x, 2.5x and 3x, respectively. We perform the experiments by applying two versions of AIF (Anisotropic Ice-Flow) model to the Greenland ice sheet. Two models (AIFa and AIFb) use the different basal sliding laws, i.e. the basal sliding velocities are estimated based on the cubic (AIFa) and linear (AIFb) power relation of the basal share stress, respectively. The changes of the ice sheet volume have shown that the models predict larger ice losses when the basal sliding is an exponential function of the basal stress as compared to the linear function. Here, we compare the results from two models to show the impact of basal sliding on the dynamic change of the Greenland ice sheet.