The performance of the Hadley Centre climate model (HADCM3) in high southern latitudes

An assessment of mean atmospheric and oceanic data from a 100-year segment of a pre-industrial control run of version 3 of the Hadley Centre climate model is presented. The model output has been verified against in situ measurements from expeditions, data from the research stations and mean fields from the 15 year re-analysis project of the European Centre for Medium-range Weather Forecasts (ECMWF). The wave number 3 pattern of the mean sea-level pressure (MSLP) and 500-hPa height fields are handled reasonably well, but the climatological troughs over the Bellingshausen Sea and at 130°E are too deep in winter by about 9 hPa at the surface. This is a result of positive sea-surface temperature (SST) errors over the tropical, eastern sides of the major ocean basins. These overly deep surface troughs result in the Antarctic coastal easterlies being too strong along the coast of Marie Byrd Land and much of the coast of East Antarctica. The circumpolar trough is too deep in summer by about 1.5 hPa and is located several degrees too far north in winter. Near-surface air temperatures over the interior of the Antarctic are in error by several degrees where the model has incorrect orographic height. The low-level temperature inversion is too strong over the Antarctic plateau. Precipitation minus evaporation over the interior of the Antarctic is slightly too low. The maximum in sea ice extent and the phase of the semi-annual oscillation (SAO) both lag the best available verification data by about 1 month.

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