Hide/Show Apps

Circulation and hydrographic characteristics of the Black Sea during July 1992

Oguz, T
Ivanov, LI
Besiktepe, S
Hydrographic measurements performed during July 1992 are used to infer sub-basin and mesoscale circulation and water mass characteristics of the Black Sea. A notable feature of the circulation is the convoluted cyclonic boundary current system with distinctly different T, S characteristics. The coastal side of the Rim Current is characterized by a series of mesoscale eddies. The interior has a weaker circulation and little marked structure within an elongated low pressure cell. The baroclinic geostrophic flow field is vertically coherent and possesses smaller amplitude meanders as compared with the previous September 1991 observation (Oguz et al.,1994). In the northwestern shelf region, the fresh water inflows from the Danube as well as Dniepr and Dniestr Rivers give rise to a strong coastal salinity front confined above the seasonal thermocline. Both the coastal current and the Rim Current exhibit strong onshore-offshore meanders, indicating significant interaction between the interior and northwestern shelf waters. The influence of the fresh water inflow can be traced up to the east of the Bosphorus exit region, similar to 32 degrees E. The anoxic interface, identified by the 16.2 sigma-t surface, is located at levels deeper than 150 m along the coast, but is elevated sharply across the Rim Current frontal zone to its shallowest position of about 100m within the interior cyclonic cell.