Wave hindcast resolution reliability for extreme analysis

Here we analyze the wave hindcast reliability for a proper description of wave climate in the Mediterranean Sea. To this aim, 6-hourly 35-years ECMWF (European Center Medium Weather Forecast) wave data at 0.7° resolution grid are compared with those provided by means of a meteocean modelling chain operative at DICCA, University of Genoa (http://www.dicca.unige.it/meteocean/) covering a 34-years temporal span at an hourly frequency on a 0.1° resolution domain. Results reveal not negligible differences in evaluating significant wave heights at peaks; in particular the tendency to underrate values in storm sea conditions performed by ECMWF dataset is here evidenced. This behavior turns directly into not-reliable long-term return level estimates for extreme wave analysis, leading to a weak description of wave climate; conversely, a wave climate robust assessment is of primary importance for maritime design.