VERTICAL STRUCTURE OF THE CURRENT FIELD IN THE NORTHERN BLACK-SEA

A possible three-layer vertical structure of the horizontal circulatio n in the Black Sea was inferred on the basis of theoretical analysis a nd laboratory tests (Bulgakov et al., 1993 a, b). The existence of an unknown anticyclonic counter-current at the main pycnocline depths (10 0-400 m) under the surface cyclonic Main Black Sea Rim current was pre dicted. It may have a horizontal scale of the order of the Rossby defo rmation radius (10-20 miles), with maximum velocity of about 0.20-0.25 m/s. To investigate the vertical structure of the current field, spec ial field observations using an OLT acoustic profiler and mooring stat ions were carried out in autumn 1993 in the Northern Black Sea. The an ticyclonic flow with the predicted characteristics was observed from d irect current-meter measurements.