Multimodel Estimate of the Global Terrestrial Water Balance: Setup and First Results

Six land surface models and five global hydrological models participate in a model intercomparison project [Water Model Intercomparison Project (WaterMIP)], which for the first time compares simulation results of these different classes of models in a consistent way. In this paper, the simulation setup is de-scribed and aspects of the multimodel global terrestrial water balance are presented. All models were run at 0.58 spatial resolution for the global land areas for a 15-yr period (1985–99) using a newly developed global meteorological dataset. Simulated global terrestrial evapotranspiration, excluding Greenland and Antarctica, ranges from 415 to 586 mm yr21 (from 60 000 to 85 000 km3 yr21), and simulated runoff ranges from 290 to 457 mm yr21 (from 42 000 to 66 000 km3 yr21). Both the mean and median runoff fractions for the land surface models are lower than those of the global hydrological models, although th