LONG-TERM SALINITY TENDENCIES IN COASTAL WATERS OF ODESSA REGION, BLACK SEA NORTH-WESTERN PART

Abstract

Long-term variability of coastal water salinity in the Odessa Region of the North-Western part of the Black Sea (NWBS) is studied using the available information on local river inflows, precipitation and wind regime. The study confirms a strong connection between the coastal water salinity in the Odessa Region, river runoff into the NWBS region and the regimes of atmospheric circulation over the North Atlantic and Europe. Using the concept of the Black Sea hydrological phases and their variations under the influence of long-term climate variability, it is predicted that the annual-mean salinity in the Odessa Region of the NWBS will increase in the coming 6-10 years. This prediction is based on the displacement of trajectories of the majority of cyclones during that period that propagate from the North Atlantic and pass over northern Europe. The displacement will favour a decrease in the Black Sea freshwater balance and, hence, an increase of salinity.
In addition, the analysis of wind regime in the Odessa Region of the NWBS in 2000-2019 reveals a decreased frequency of westward winds and a significantly increased frequency of northerly winds. Assuming that these wind trends continue in the future, and taking into consideration the major hydrodynamic features of the NWBS, it is expected that it will lead to a blocking of freshwater inflow from the Dnieper River mouth into the northern and western coasts of the region. As a result, the increase of annual salinity in the coastal waters will intensify.