A comparison of modelled precipitation in Greenland

Abstract: The Greenland ice sheet develops throughout the year with the changing weather condi- tions. Precipitation contributes by increasing the mass, whilst warmth induces melting, which makes the ice sheet diminish. The term Surface Mass Balance (SMB) is used for the isolated gain (accumulation) and melting (ablation) of the surface of the ice sheet and is therefore important for understanding future rates of sea level rise. This study compares the modelled precipitation from Regional Climate Model (RCM) HIRHAM5 and the Numerical Weather Prediction (NWP) model HIRLAM 7.3 to assess the chal- lenges for RCMs and NWP models to accurately simulate accumulation rates on a local scale and the consequent impact on SMB uncertainty. It is concluded that HIRLAM 7.3 is an overall wetter model than HIRHAM5 for the studied region. One noticeable bias come from the different physiographic fields of orography, mountain like terrain, in the two models. It is also suggested that future studies should compare model output with observations to further assess model biases.