The Institute of Marine Research, the Bjerknes Centre for Climate Research in Norway, and the University of Bergen researchers recently conducted a study which demonstrates the warming of northwest Barents Sea during recent years.
"A warm deep current enters the Barents Sea from the north. The current is a branch of the Arctic Ocean Boundary Current. The branch enters the Barents Sea below the ice cover and the colder and fresher upper waters (shown in blue). © 2012 Sigrid Lind"
The subsurface Atlantic Water in the northern Barents Sea showed high temperature increase in the late 1990s, The warming of Atlantic Water in the North Atlantic Ocean partly increases the temperature in that region. The warm deep current flowing within the Barents Sea from the north was driven by a regional wind pattern.
The Arctic Ocean channels the warm deep current to flow within the Barents Sea below colder upper waters. As a part of Arctic Ocean Boundary, the current flows between Svalbard and Franz Josef Land, bringing warm Atlantic Water within Barents Sea. While on its way, the Atlantic Water blends with the cold waters above that thus protecting the ice cover.
The study contends that easterly winds across the Barents Sea shelf-slope will escalate the Arctic Ocean Boundary Current, further driving the Atlantic Water within Barents Sea. The regional wind pattern supported the easterly winds by the end of 1990s and early 2000s. The easterly wind is related to the dipole pattern of Arctic’s near surface atmospheric pressure.
The cold waters in the north of Barents Sea serve as border from warmer water in the Polar Front, thereby preventing the warm water from entering northern Barents Sea. The cold waters therefore protect the seasonal ice cover of the Barents Sea. The warm Atlantic Water entering the Barents Sea from the north may pose risk to the ice cover. The Atlantic Water is saline besides being warm and its inflow from the north will therefore make the cold upper waters more saline. Increase in density and salinity will therefore decrease the intensity of the Polar Front. The warm water further south, passing the Polar Front will decrease the ice extent, thereby affecting the ecosystem, and beyond.
Source: http://www.bjerknes.uib.no/