Spatial analysis of seasonal patterns in sea surface temperature and salinity distribution in the Black Sea (1992-2017)

Abstract

Sea water temperature and water salinity one of the most important environmental factors of the marine ecosystems. Both of them plays an important role in forming suitable environment for marine living organisms and have a great impact on species biodiversity. Our goal for this paper was to identify spatial patterns of interannual variations in the salinity and temperature fluctuations to understand possibilities of future change of the Black Sea ecosystem and its impact on fisheries. We used temperature and salinity data from CMEMS for the 1992-2017 time period. All downloaded data was processed by QGIS 3.14 and R 4.0.3. We found that the temperature regime of the Black Sea in different periods of the year is determined by three main factors - the depth of the shelf zone, the influence of river runoff, and water circulation due to currents. The average salinity of the Black Sea waters is 19 ‰, areas with lower salinity are located near the west shore, due to the flows from the largest rivers (Dnieper, Dniester, Danube) bringing a large amount of fresh water to the Black Sea. The area with higher salinity is located in the south- west due to the water exchange of the Black Sea with the saltier Sea of Marmara (∼ 26 ‰) through the Bosphorus. The currents of the Black Sea pick up the salty water of the Sea of Marmara and slowly moving the water column against the clockwise, carry it across the entire Black Sea, thereby increasing its average salinity.