Task 2.1 Investigate the surface mass balance and dynamical response of the Greenland Ice Sheet to past and present Arctic sea ice changes.
The novel reconstructed Sea surface Temperatures (SSTs) and sea ice coverages in Work package 1 will be used as boundary conditions for the Atmospheric Global Climate Models ( AGCMs) to simulate the surface mass and energy balance over Greenland Ice Sheet. High-resolution surface mass and energy balance fields will then be obtained for each of the time slices using regional climate models (HIRHAM and WRF) to further downscale the AGCM circulations and the surface mass balance. This unprecedented set of high-resolution surface mass and energy balance will be used to drive a suite of different ice sheet models. Since differences in the complexity of the represented physical processes in the models cause diverging results, this intercomparison helps to explore the uncertainty range of the ice sheet response. Contrasting the results of higher complexity models (FEM) with simpler models (PISM, CISM) reveals potential weaknesses in the current generation of coupled ESM-ISMs. In addition, the coarse resolution SMB produced by AGCMs will be compared with the high resolution one to address the impact of the resolutions on simulating the ice sheet.