Mapping of precipitation in Iceland using numerical simulations and statistical modeling

Rögnvaldsson, Ólafur; Crochet, Philippe; Ólafsson, Haraldur


Precipitation in Iceland during a period of 10 years is simulated with the PSU/NCAR MM5 model. The results are compared with precipitation estimated by a statistical model based on observations and a number of topographic and geographic predictors. The simulated precipitation pattern agrees with the statistical model in areas where data is available and gives a credible precipitation pattern in data-sparse mountainous regions. The simulation is however in general overestimating the precipitation, but the magnitude and the seasonal and geographical distribution of the overestimation indicate that it is to some extent associated with observation errors that are due to wind-loss of solid precipitation. There are also uncertainties associated with the representativeness of the observations as well as with the reference model itself.