Cassano, J.J., J.E. Box, D.H. Bromwich, L. Li, and K. Steffen, 2001: Evaluation of Polar MM5 simulations of Greenland's atmospheric circulation. J. Geophys. Res., submitted.
Abstract
A complete annual cycle over the Greenland ice sheet is simulated with the Polar MM5, a mesoscale model optimized for use over extensive ice sheets. These simulations are compiled from a series of short duration (48 h), forecast mode, simulations. The model output is verified primarily with the Greenland Climate Network automatic weather station (AWS) array, over time scales from annual to diurnal. The model simulations show a high degree of skill for all variables verified with the AWS data (pressure, temperature, water vapor mixing ratio, wind speed and direction, downwelling shortwave radiation, and net radiation) over all time scales considered, although the use of a fixed albedo in the Polar MM5 leads to large errors in the simulated net radiation budget over melting ice surfaces during the summer months. The modeled precipitation distribution agrees with available observations in the interior of the ice sheet, but is excessive along the steep margins of the island. A discussion of possible future applications of the Polar MM5 is presented.
This research was supported by the Office of Polar Programs, National Science Foundation.