DYNAMIC PROCESSES IN ANIVA BAY (SAKHALIN) FROM RESULTS OF INSTRUMENTAL MEASUREMENTS IN THE FALL OF 2000

G. V. Shevchenko and V. N. Chastikov

Data of observations at an autonomous buoy station in Aniva Bay (southern Sakhalin) at 7, 35, and 75 m in the fall of 2000 are analyzed. Oceanographic surveys at the cross section passing through the buoy station are used. The inflow of relatively warm and freshened water of the East Sakhalin Current was detected from a temperature jump of greater than 10ºC at 75-m depth in early October 2000. This also caused considerable changes in the distributions of the oceanological parameters in the bay. Quasi-cyclic oscillations with a period of about 12 days were observed at 35 m. They were associated with an anticyclonic vortex. The flow directed northward, to Aniva Bay, prevailed in the bottom layer. In early November, the vortex was driven away from the buoy station and the flow became barotropic. The chlorophyll-a concentration in the surface layer increased sharply, which suggests that the phytoplankton-rich water was advected by the East Sakhalin Current to the bay. Inertial currents of clockwise rotation with a mean velocity of about 20 cm/s were caused by the interaction between the East Sakhalin Current and the quasi-stationary anticyclonic vortex slowly rotating in the bay.