A preliminary investigation of boreal winter and boreal summer seasonal prediction is conducted with the Center for Ocean-Land-Atmosphere Studies (COLA) atmospheric general circulation model (AGCM). For each season, ensembles of three integrations initiated from observed atmospheric states one day apart are done for five different years using prescribed observed seasonally varying sea surface temperature (SST). The model veracity is assessed by comparing the 15 member ensemble means of geopotential height at 300 hPa and precipitation for each season to the corresponding observations.
To address the impact of observed SST on prediction, these 30 integrations are repeated using prescribed seasonally varying climatological SST. The model's skill in reproducing the observed interannual variability in geopotential height at 300 hPa and precipitation over different regions is analyzed. In agreement with published results, the greatest skill in reproducing the observed interannual variability in the geopotential height field is found in the tropics and in the North American region during boreal winter. Skillfull prediction of precipitation is found to be more difficult, with the only potentially useful skill occurring over the central U.S. during boreal summer.
Complete copies of this report are available from:
Center for Ocean-Land-Atmosphere Studies
last update: 1 July 1996
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