Intercomparison of Hydrologic Processes in AMIP GCMs

Abstract

Abstract Results of an intercomparison study under the Atmospheric Model Intercomparison Project (AMIP) to assess the abilities of 29 global climate models (GCMS) in simulating various aspects of regional and hydrologic processes in response to observed sea surface temperature and sea ice boundary forcings are presented. The authors find that the models generally portray an earthlike climate to approximately 10%–20% of the global land surface temperature (=14.8°C) and global precipitation (=2.3 mm day−1). While a majority of the models have a reasonable global water budget, about a quarter of the models show significant errors in the total global water balance. While the model frequency distributions of heavy precipitation associated with deep convection are in reasonable agreement with observations, a systematic underestimate of the frequency of occurrence of light precipitation events (< 1 mm day−1) is present in almost all the AMIP models, especially over continental desert regions and over tropical an...