REGIONAL VALIDATION OF MEANS, VARIANCES, AND SPATIAL PATTERNS IN GENERAL-CIRCULATION MODEL CONTROL RUNS

The focus of this study is the control run performance of four general circulation models (GCMs): the Oregon State University (OSU) two-layer atmospheric GCM (AGCM), the OSU coupled ocean-atmosphere model (CGCM), the Goddard Institute for Space Studies (GISS) nine-layer AGCM, and the European Centre for Medium-Range Weather Forecasts (ECMWF) T21 model. The analysis variable is monthly mean sea level pressure (MSLP), and model validation is performed for a limited domain (North America/Atlantic/Europe). The significance of the local (grid point by grid point) differences in means and variances is then determined by performing univariate t- and F-tests. Results indicate that all four models have highly significant errors in the mean field and spatial pattern over the entire annual cycle. The ECMWF T21 model simulates the spatial pattern and time-mean MSLP field with greater fidelity than the other models considered here. -from Authors