The characteristics of wind and wave fields modelled with different resolutions

A number of meteorological situations are studied using the operational models at the European Centre for Medium-Range Weather Forecasts, and a series of short-term forecast experiments is made for four different resolutions of the meteorological model. A comparison with the measurements and between the corresponding results allows an evaluation of the relative benefits of increased resolution. The focus is on the surface wind speeds and on the wave heights. Good quality results are found over the oceans, especially in areas with strong spatial gradients. Consistent with the already good quality of the present operational results, the improvements with increased resolution are small, but significant. In enclosed basins, as in the case of the Mediterranean Sea, it is found that both the surface wind speed and wave height are strongly underestimated. The improvements with increased resolution are greater than over the oceans, but still not sufficient to give agreement with measured data.