Annual trends in storm wave intensity over the past 41 years were evaluated during the present study. Storm wave intensity is evaluated in terms of total storm wave energy (TSWE) and storm power index (SPI) of Dolan and Davis (1992). Using an accurate long-term wave hindcast developed using a calibrated SWAN model, all storm wave events occurring over the past 41 years were characterized in terms of significant wave height (H_s) and total storm duration. Thus, both SPI and TSWE was computed for each storm wave event. The Theil–Sen slope estimator was used to estimate the annual slopes of the SPI and TSWE and the Mann–Kendall test was used to test the trend significance with different confidence levels. The present study is spatially performed for the western Mediterranean Sea basin considering 2308 grid points in a regular grid of 0.198° resolution in both directions. Results allow as to define five hotspots covering a large area, experienced a significant increasing slope in both SPI and TSWE (annual maxima and average). The confidence level in this area exceed 95%, with a steep slope between 100 kWh·m⁻¹·year⁻¹ and 240 kWh·m⁻¹·year⁻¹ for annual max TSWE and between 28 m²·h·year⁻¹ and 49 m²·h·year⁻¹ for annual max SPI. Consideration of the present findings is strongly recommended for risk assessment and for sustainable development in coastal and offshore area and to identify areas sensitive to global climate change in the western Mediterranean Sea.

This study aims to investigate the quality of ERA5, a recent reanalysis wind product, and its contribution to wave modelling performance in a semi-closed sea, the Black Sea. This investigation includes a comparison of ERA5 surface wind fields with the ones from the CFSR to assess if this latest reanalysis improved the representation of the surface winds. Wind speeds from both reanalyses were validated with measurements at Gloria, the only sea wind measurement station on the Black Sea. Validations were also conducted using altimeter and scatterometer satellite data after which results were later compared against each other. The second aim of this study investigates whether a wave hindcast model forced with the ERA5 wind fields has improved prediction of wave parameters. A SWAN model with default settings was used to compare the results under the same conditions. Performance analyzes of the default SWAN wave estimates with both ERA5 and CFSR winds were conducted using three offshore buoy measurements and altimeter data of satellites over the Black Sea. Results show that ERA5 winds are more biased compared to CFSR winds at Gloria location. Both CFSR and ERA5 underestimate wind speeds. ERA5 performs better than the CFSR in lower wind speeds and worse in higher wind speeds. However, ERA5 winds have less bias and are more scattered than the CFSR winds against the satellite data. SWAN driven by CFSR winds performs better than the one driven by ERA5 winds against both buoy and satellite data.