ON IMPROVED MESOSCALE FORCING

Analyses and forecasts generated in Numerical Weather Prediction, NWP, do generally not contain mesoscale wind information over the oceans due to the lack of surface forcing and the sparsity of 3D weather observations. The Advanced scatterometer, ASCAT, was launched on 19 October 2006 as the third wind scatterometer currently in space joining up with the ERS-2 and the SeaWinds scatterometers. Scatterometers measure the radar backscatter from wind-generated cm-size gravity-capillary waves and provide high-resolution wind vector fields over the sea with high quality. In this paper we illustrate and discuss the lack of mesoscale information in NWP models and the improved surface forcing fields brought by scatterometers.