Observations on the Rim Current structure, CIW formation and transport in the western Black Sea

Oguz T., Besiktepe S.

DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, vol.46, no.10, pp.1733-1753, 1999 (SCI-Expanded) identifier identifier


CTD and ADCP measurements together with a sequence of satellite images indicate pronounced current meandering and eddy activity in the western Black Sea during April 1993. The Rim Current is identified as a well-defined meandering jet stream confined over the steepest topographic slope and associated cyclonic-anticyclonic eddy pairs located on both its sides. It has a form of highly energetic and unstable flow system, which, as it propagates cyclonically along the periphery of the basin, is modified in character. It possesses a two-layer vertical structure with uniform upper layer speed in excess of 50 cm/s (maximum value similar to 100 cm/s), followed by a relatively sharp change across the pycnocline (between 100 and 200 m) and the uniform sub-pycnocline currents of 20 cm/s (maximum value similar to 40 cm/s) observed up to the depth of similar to 350 dbar, being the approximate limit of ADCP measurements. The cross-stream velocity structure exhibits a narrow core region (similar to 30 km), flanked by a narrow zone of anticyclonic shear on its coastal side and a broader region of cyclonic shear on its offshore side. The northwestern shelf circulation is generally decoupled from the influence of the basinwide circulation and is characterized by much weaker currents, less than 10 cm/s. The southward coastal flow associated with the Danube and Dinepr Rivers is weak during the measurement period and is restricted to a very narrow coastal zone.