Impact of wind field horizontal resolution on sea waves hindcast around Calabrian coasts.

We investigate the impact of wind field enhanced horizontal resolution on sea wind wave hindcast around Calabrian coasts, the southernmost tip of the Italian peninsula. Simulations are performed by WAM (WAve Model), a third generation state of the art wave model. In order to study this topic, we discuss two simulations sets. First set forces WAM by ECMWF (European Centre for Medium-Range Weather Forecasts) surface wind field analysis, used in this paper with a resolution of 0.5°; for the second simulation set RAMS (Regional Atmospheric Modeling System) surface wind field forces WAM. Initial and dynamic boundary conditions for RAMS simulations, that have 20 km horizontal resolution, are derived from ECMWF analysis. To obtain a reliable statistical data set, integrations are performed for six months from 1st October 2003 to 31th March 2004. We evaluate performance comparing the WAM modelled wave heights and directions against data of Wave measuring Buoys (WBs) moored off Cetraro and Crotone. Statistical tests are performed to assess differences between modelled data and measurements and between modelled data sets. Results show better performance for wave height field when RAMS forces WAM. Improvements are larger for Crotone, but differences between simulated and measured wave height distributions are significant at 99% statistical level. Simulated wave directions are generally good for the model set-up used in this paper and differences between modelled data sets are minor. PACS: 92.60.Gn Winds and their effects PACS: 92.10.Hm Surface waves, tides, and sea level PACS: 92.10.Kp Sea-air energy exchange processes