Thermohaline Water Structure on the Southwestern Chukchi Sea Shelf under Conditions of Opposite Regimes of Atmospheric Circulation in Summer Periods of 2003 and 2007

N. S. Vanin

The results of two oceanographic surveys, carried out by TINRO-Center in August 2003 and 2007 in the southwestern part of the Chukchi Sea under conditions of opposite regimes of atmospheric circulation in the Eastern Arctic, are given. A stationary anticyclone with the center over the Beaufort Sea in 2007 favored the transport of warm air masses to the Arctic basin and more rapid ice melting. The surface layer temperature to the east of Wrangel Island reached 12C (6–8C above the normal). The upwelling of bottom waters was registered in the coastal zone due to the southeastern winds, the Siberian coastal current was not observed. In summer 2003, on the contrary, the cyclonic circulation type prevailed over the eastern seas of the Arctic, the northwestern winds in the coastal zone favored the spreading of the Siberian coastal current almost up to Bering Strait, the water temperature was 2–3C below normal. The coastal thermal front was formed in both situations: in the first case, due to upwelling, in the second case, due to the spreading of cold coastal desalinated East Siberian waters.