SIMULATION OF ATMOSPHERIC CIRCULATION DURING THE GIMEX-91 EXPERIMENT USING A MESO-GAMMA PRIMITIVE EQUATIONS MODEL

A meso-gamma-scale atmospheric model has been used to simulate atmosph eric 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 s ynoptic-scale wind forcing is included. The tundra topography is assum ed to be either flat, or averaged over a 50-km-wide cross section cent ered 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 sensiti vity of the model results to the synoptic-scale wind forcing is signif icant. The impact of a tundra much warmer than the ocean on the ice sh eet melting is discussed. It is found that weak easterly synoptic-scal e winds are able to overwhelm this impact, especially when the tundra is assumed to be flat.