Simulation of Atmospheric Circulation during the GIMEX 91 Experiment Using a Meso-γ Primitive Equations Model

Abstract

A meso-?-scale atmospheric model has been used to simulate atmospheric circulations observed during the Greenland Ice Margin EXperiment (GIMEX). The simulations shown here are two-dimensional and cover the 12?13 July 1991 period, a typical summer situation in this area. The synoptic-scale wind forcing is included. The tundra topography is assumed to be either flat, or averaged over a 50-km-wide cross section centered on the GIMEX transect. Simulated wind, temperature, humidity, and turbulent fluxes compare reasonably well with available observations. The simulated heat used to melt snow or ice is also shown. The sensitivity of the model results to the synoptic-scale wind forcing is significant. The impact of a tundra much warmer than the ocean on the ice sheet melting is discussed. It is found that weak easterly synoptic-scale winds are able to overwhelm this impact, especially when the tundra is assumed to be flat.