In the Barents Sea warm, salty Atlantic water from the south meets cold and fresher Arctic Water from the north. Atlantic Water is both pushed northwards by southwesterly winds and pulled by the sinking waters as they cool. Currents occur at a range of time and space scales.
Ocean temperatures measured by Russia at the Kola section reveal changes over time. The measurements cover inter-annual, decadal and multidecadal periods.
Decadal oscillations in temperature in the Barents Sea and the Labrador Sea are linked and multidecadael temperature changes occur in both the North and South Atlantic.
More heat to the Barents Sea
The NAO index is based on the difference of sea level pressures between the Azores and Iceland. Low NAO implies weak westerly winds. A high NAO implies strong westerly winds.
When winds intensifies, the Atlantic water flow becomes stronger and narrower. Less heat is lost to the air and more heat flows to the Arctic Ocean and the Barents Sea.
Zooplankton species prefer different temperatures, therefore inhabiting different areas. Recent warming has caused zooplankton to shift northwards. While warm-water zooplankton have invaded the habitat, those preferring cooler conditions have abandoned the area.This shift has an impact on fish and mammals who feed on the zooplankton.