CLIMATE CHANGE IMPACTS ON THE HYDROLOGICAL AND HYDROCHEMICAL CHARACTERISTICS OF THE NORTHERN CASPIAN
This paper analyses the climate changes observed in recent years in the Caspian Sea region, and assesses their impact on the main hydrological and hydrochemical characteristics of the marine environment in its North-Western part. Significant differences in the thermohaline structure and oxygen regime of the water area in the Northern Caspian were revealed in the periods, which were selected on the basis of the analysis of long-term data and corresponded to the periods of rising (1978-1995) and falling of the sea level (1996-2015). Increasing sea temperatures caused by the continuing warming of the atmosphere in the Caspian basin, and the decline of the Volga inflow lead to dependence hydrological-hydrochemical characteristics on the local hydrodynamic and biological processes in the Northern Caspian. Further increase in seawater temperature will lead to a decrease in the concentration of dissolved oxygen, which plays a major role in the development of marine biota. If the current climate trends persist for a long time, they are likely to have adverse consequences for the marine ecosystem.