Wave climate projections in the Western Black Sea using regional EURO-CORDEX wind forcing data

This paper presents an assessment of the changes in wave parameters and surface Stokes drift in the western Black Sea towards the end of the 21st century under three different projected scenarios: RCP2.6, RCP4.5 and RCP8.5. Wave projections were generated using the wave model WAM forced by high-resolution CORDEX-EU wind fields from SMHI (Swedish Meteorological and Hydrological Institute), while hindcast simulations driven by ECMWF (European Centre for Medium-Range Weather Forecasts) ERA5 reanalysis winds were used to validate the wave model's performance and evaluate the historical wave conditions. The projected changes in significant wave height, mean wave period, and Stoke drift were estimated by comparing the future runs for the period 2070–2100 with historical runs for the period 1975–2005. One key finding is that the changes in wave parameters and Stokes drift are more significant under RCP2.6 than under other scenarios, especially in winter. In contrast, significant decreases in these parameters are observed in summer under RCP8.5. The intensity and duration of extreme events are projected to increase by approximately 20 % under both RCP2.6 and RCP8.5 during winter in the western Black Sea. These projected changes suggest substantial impacts on the transport of floating particles, coastal morphology, Langmuir turbulent mixing, ocean circulation, and wave energy in the future. • Long-term wave simulations were downscaled for the Western Black Sea using high-resolution CORDEX-EU11 wind forcing data. • Wave parameters and Stokes drift are significantly higher than historical values under RCP2.6 during winter but are substantially reduced under RCP8.5 in summer by the end of 21st century. • The intensity and duration of extreme wave events in the western Black Sea are projected to increase by approximately 20 % during winter under both RCP2.6 and RCP8.5.