Supervisors info:
Σαράντης Σοφιανός, Αναπλ. Καθηγητής, Τμήματος Φυσικής, ΕΚΠΑ
Διονύσιος Ραΐτσος, Επικ. Καθηγητής, Τμήματος Βιολογίας, ΕΚΠΑ
Βασίλειος Βερβάτης, Συνεργάτης Ερευνητής, Τμήματος Φυσικής, ΕΚΠΑ
Summary:
Black Sea Water (BSW) inflow into the Aegean Sea is of great importance for shaping the hydrography and circulation patterns not only in the Aegean, but also across the entire Eastern Mediterranean Sea. In addition to its influence on the region's physical processes, the exchange water fluxes through the Dardanelles Strait can also exert a significant effect on its biogeochemical characteristics. In this study, we employ a twin numerical model experiment to investigate the impacts of the BSW inflow into the Aegean Sea, from both physical and biogeochemical perspectives. To accomplish this, we utilize a coupled ocean–biogeochemical configuration of the ocean model NEMO (Nucleus for European Modelling of the Ocean), covering the Mediterranean and Black Seas at 1/12° resolution. The twin experiment comprises two simulations: one representing the actual conditions of the study region, with BSW flowing into the North Aegean, and the other depicting a hypothetical scenario in which the Dardanelles Strait is sealed off, resulting in a complete absence of BSW inflow into the study area. The experiments were carried out for a 5-year period, from 2008 to 2012. In the results, we focus on the last year (2012), showcasing the variations of several upper-ocean and vertical thermohaline and biogeochemical properties, for each experiment, as well as for their difference. In summary, we find that BSW has a pronounced impact on various properties and processes of the North Aegean Sea. Some of the most important outcomes are the significant reduction in Sea Surface Salinity levels, the intensification of the mesoscale eddies of the region and, potentially, the hindering of deep water formation processes. Additionally, the presence of BSW leads to higher levels of chlorophyll and nutrients in the North Aegean, while oxygen concentrations rise on the surface and decrease in deeper layers of the study area.
Keywords:
Ocean Modelling, twin experiment, NEMO, Aegean, Black Sea Water
