High-resolution simulations of the surface mass balance of Greenland at the end of this century

Abstract

Abstract. We present atmospheric general circulation model simulations of the present (1981–2005) and future (2081–2100) climate according to the SRES A1B greenhouse gas scenario. Focusing on Greenland, we use a stretched grid in the global model, thereby reaching a horizontal grid spacing of 60 km in the region of interest. This allows to capture reasonably the escarpment zone of the ice sheet. For the end of this century, the model suggests a precipitation increase in the central region of Greenland, which is overcompensated for by a strong increase of meltwater production in the lower areas. We calculate the changes of water fluxes into the adjacent seas according the simulated surface mass balances changes. The calculated freshwater flux at the end of the 21st century appears too weak to induce a significant reduction of the meridional overturning circulation in the North Atlantic. The resulting surface mass balance decrease between the last decades of the 20th and 21st centuries is equivalent to a positive contribution of 0.8 mm yr−1 to global eustatic sea-level rise.