Arctic Precipitation and Evaporation: Model Results and Observational Estimates

Abstract

Abstract Observational estimates of precipitation and evaporation over the Arctic Ocean and its terrestrial watersheds are compared with corresponding values from the climate model simulations of the Atmospheric Model Intercomparison Project (AMIP). Estimates of Arctic regional mean precipitation from several observational sources show considerable scatter, and the observational estimates based on gauge-adjusted station data are considerably larger than the other observational estimates. While the AMIP model simulations of precipitation also show scatter, the ensemble mean of the models’ precipitation exceeds even the higher (gauge-adjusted) observational estimates over the Arctic Ocean and its major watersheds. The difference between simulated precipitation and evaporation (P − E), representing the net freshwater gain (runoff) by the surface, also exceeds the observational estimates by 44%–83% over the Arctic Ocean and by generally smaller percentages over the terrestrial watersheds. The ensemble model m...