Impacts of three severe storms on Aegean Sea oceanography (2018–2020)

This study presents a comprehensive analysis of the impacts of severe storms on the oceanography of the Aegean Sea, with specific focus on storms occurring on 15 November 2018, 14 September 2019, and 7 January 2020. Notable changes in oceanographic variables are observed on the storm day and in the subsequent days, gradually returning to pre-storm conditions. During storms, Aegean Sea surface temperatures were 2–3 °C below average, with cooling particularly evident along the west coast and northern part. Salinity increases of 0.5–1 PSU are observed during storms, with the most significant effects noted on 7 January. Storms consistently led to a decrease in sea level in our study area, with the western coast and north Aegean Sea experiencing levels 6–10 cm lower than the monthly average. Surface currents along the west coast and within latitudes 36–40° are 0.3 to 0.4 m/s stronger than average during storms. Storm-induced changes in the Thracian Sea’s anticyclonic gyre on 5 January reveal a speed increase of 0.3–0.4 m/s. Notably, both temperature and salinity fluxes exhibit significant changes during storms, characterized by a shift from east-to-west transport, contrasting with the west-to-east pattern observed before the storms. This shift is mainly influenced by Ekman transport, which predominantly directs water westward and north-westward when the wind comes from the northeast to southwest. Storms contribute to heightened salinity, increased kinetic energy, and enhanced transport, accompanied by a decrease in temperature, with the most pronounced effects near the surface along vertical layers.