Climate simulations with the HIRHAM limited area regional climate model over Scandinavia

The hydrological cycle on a regional scale is poorly represented with present-day coarse resolution general circulation models (GCMs). With a dynamical downscaling technique, in which a regional higher-resolution climate model (RCM) is nested into the GCM, this starts to become feasible. Here we apply an RCM with a very high resolution over an area covering the Scandinavian Peninsula. A time-slice simulation is performed with the driving boundary conditions taken from a coupled ocean-atmosphere GCM experiment. Local effects become better resolved and more realistically simulated. Effects of resolution are investigated through a comparison of sub-area averages. We find in particular that in mountainous regions the high-resolution simulation shows improvements in the simulation of runoff. It does, however, inherit certain large-scale systematic errors from the GCM.