Ensembles of boreal summer coupled land-atmosphere climate model integrations for 1987 and 1988 are conducted with and without interactive soil moisture to evaluate the degree of climate drift in the coupled land-atmosphere model system, and to gauge the quality of the specified soil moisture data set - from the Global Soil Wetness Project (GSWP). Use of specified GSWP soil moisture leads to improved simulations of rainfall patterns, and significantly reduces root mean square errors in temperature, indicating that the GSWP product is useful and can also be used to supply initial conditions to fully coupled climate integrations. Integrations using specified soil moisture from the opposite year suggest that the interannual variability in the GSWP data set is significant, and contributes to the quality of the simulation of precipitation above what would be possible with only a mean annual cycle climatology of soil moisture. In particular, specification of soil wetness from the wrong year measurable degrades the correlation of simulated precipitation and temperature patterns compared to observed.
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Center for Ocean-Land-Atmosphere Studies
last update: 10 Sebtember 1999
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