Gravity waves resolved in ECMWF and measured by SABER

Abstract

[1] The limited resolution of most general circulation models (GCMs) is not sufficient to simulate gravity waves (GWs) explicitly. ECMWF (European Center for Medium-Range Weather Forecasts) data have now a horizontal resolution of 1/4°, so parts of the mesoscale GWs can be resolved although most source processes still contain subgrid phenomena. We validate the GWs resolved in ECMWF by comparison with corresponding results obtained from global SABER (Sounding of the Atmosphere Using Broadband Emission Radiometry) satellite observations. For this comparison, effects of the radiative transfer and satellite retrieval procedure are accounted for. Globally, GWs can be attributed to various GW sources and the GW spectrum is modulated by the background winds. Correlation analysis comparing SABER and ECMWF temperature fluctuations indicate good agreement with respect to mountain waves, for example, over the southern tip of south America or over Scandinavia, as well as GWs at the edge of the winter polar vortex. Copyright 2009 by the American Geophysical Union.