Air-snow interactions and the surface energy and mass balance over the melting zone of west Greenland during the Greenland Ice Margin Experiment

Abstract

A meso-γ-scale atmospheric model coupled to a snow/ice model has been used to study the atmospheric circulation observed during the Greenland Ice Margin Experiment [Oerlemans and Vugts, 1993] and its impact on the ice sheet mass balance. The simulations shown here are two dimensional and cover the July 5-24, 1991, period, a typical fine weather period in that area. The synoptic scale wind, temperature, and humidity evolution are included. Simulated wind and temperature compare reasonably well with available observations. The simulated snow/ice melting is examined, and the sensitivity of the model to the ice-sheet surface representation is discussed by replacing the snow/ice model by a classical force-restore model. It is found that the melting-refreezing of liquid water in the snow pack impacts significantly the surface energy and mass balances of the ice sheet. In particular, the nighttime surface temperature minimum and katabatic wind speed are less marked when the refreezing process is activated in the model. Copyright 1997 by the American Geophysical Union.