Evaporation over heterogeneous land surfaces—comparison between models and experiment

To account for the subgrid variability of the evaporation over heterogeneous land surfaces within numerical weather prediction models we have taken measurements of the heat fluxes over different land surfaces: During the experiments LITFASS 1998, 2002 and 2003 the heat fluxes were measured together with atmospheric and soil data. These heat fluxes were compared with the land surface models TERRA/LM of the Deutscher Wetterdienst and the REMO/ECHAM model of the Deutsches Klimarechenzentrum using different averaging strategies at the grid/pixel scale and using a parameter optimization approach. We applied the shuffled complex evolution algorithm of the University of Arizona to determine optimal parameters of the model and validated the models. We show some preliminary results for the area around Lindenberg (Germany).