SEASONAL AND INTERANNUAL VARIATIONS OF OCEANOGRAPHIC CONDITIONS IN THE SOUTHERN TATAR STRAIT

G. V. Shevchenko and V. N. Chastikov

Seasonal variability of oceanographic conditions in the southern Tatar Strait is described from mean long-term temperature and salinity values using observations at standard oceanographic section Cape Slepikovsky—Cape Zolotoy (April—December). Flow velocity was calculated for each month in the geostrophic approximation. It is shown that the velocity of the Tsushima Current near its northern boundary decreases from spring to fall, with a maximum attaining 15 cm/s. Off the Sakhalin coast, there is a narrow strip of the West Sakhalin Current, whose velocities increase from 20 cm/s in spring to 35—40 cm/s in the fall. Sustained northerlies and northwesterlies, typical of the cold season, may be the possible cause of the fall intensification of the current. The results of twelve surveys performed by the Sakhalin Research Institute for Fisheries and Oceanography in 1997—2003 show significant deviations of oceanographic conditions from estimated norms for different years [10]. Maximum water temperature and salinity anomalies (above 30ºC and 0.45‰) are normally observed in the surface layer; their magnitude and statistical significance decrease with depth, but on some occasions there is an opposite picture. Velocities of the West Sakhalin Current varied between 5 and 50 cm/s.