Характеристика и особенности океанологических условий североохотоморского шельфа осенью 2004 г.

Thermohaline and dynamic conditions of the northern Okhotsk Sea shelf are considered on the data of oceanographic survey conducted by R/V Professor Kaganovsky in September-October of 2004. The conditions are compared with climatic ones for the period 1998-2004. In the autumn of 2004, SST was relatively cold, but water temperature below seasonal thermocline was relatively warm. A problem of winter severity influence on the following summer conditions in surface and subsurface layers of the Okhotsk Sea is discussed. The period of "cool" subsurface layer in autumns of 1998-2001 coincides with the period of high winter ice cover in the Okhotsk Sea averaged for December-June. In the case of 2004, low ice cover in the winter 2003-2004 preceded the abnormally high temperature in subsurface layer and at the sea bottom in the autumn of 2004. Geostrophic calculation relative to 300 db surface revealed a cyclonic circulation over the northern Okhotsk Sea shelf in the autumn of 2004, with expressed Yamskoye, North-Okhotsk, and Amur Currents. The intensification of the currents is explained by water freshening along the coast and relatively salt water penetration from deep-sea area to the central part of the shelf.