The climate of the Greenland Ice Sheet as simulated by Polar MM5

Polar MM5 is a version the fifth generation Pennsylvania State University (PSU) / National Center of Atmospheric Research (NCAR) mesoscale model (MM5) developed by the Polar Meteorology Group of the Byrd Polar Research Center at The Ohio State University for use over polar ice sheets (http://www-bprc.mps.ohio-state.edu/PolarMet/pmm5.html). The Greenland climate has not been explored thoroughly due to the shortage of observations over the ice sheet. Ten years of simulations from 1991 to 2000 over Greenland by Polar MM5 with two nested domains are run to describe the ice sheet climatology. The fine domain horizontal spacing is 24km, covering the entire Greenland Ice Sheet and Iceland. In vertical, the model has 28 levels. The initial fields and boundary conditions are interpolated from ECMWF TOGA archived data. Each model runs from 0000UTC on first day to 0600UTC the next day, with last 24 hours of output used for analysis and the first 6 hours being discarded for model spin-up reasons. Greenland AWS observations are used to verify Polar MM5 performance. The results include the annual mean and seasonal cycle of precipitation, surface wind, near surface temperature inversion, cloud fraction, moisture content and cyclonic activity. The interanual variability of these climatological variables in relation to the North Atlantic Oscillation (NAO) index is also explored.