Signals in the freshwater outflow out of the Arctic Ocean

Rabe, B.; Holfort, J.

EGS - AGU - EUG Joint Assembly, Nice, France, 6 - 11 April 2003.

The freshwater outflow out of the Arctic Ocean into the Nordic Seas is extremly high in some years. We compare two big events, the 'Great Salinity Anomaly' of 1969 and the sea ice export anomaly through the Fram Strait in 1994. Different driving mechanisms caused different effects on the Northern North Atlantic and the Nordic Seas. The 'Great Salinity Anomaly' (an advective event) was the result of a big freshwater export from the Arctic Ocean. A low pressure cell expanding from the Iceland Sea to the Barents- and Kara Sea existed and caused a stronger and bigger Transpolar Drift Stream. This helped to export this anomaly out of the Nordic Seas into the North Atlantic proper, where it could be traced around the North Atlantic for several years. The ice export anomaly of 1994 through the Fram Strait occured while the NAO Index was at one of the highest levels in this century. But this anomaly did not have such an influence on the ocean since the NAO Index dropped to a very low level the winter after the high export. Therefore the freshwater anomaly did not reach the Northern North Atlantic and stayed in the Nordic Seas. On the basis of data we show the different evolutions of these events in the Nordic Seas and the Northern North Atlanic and that the differences are due to different climate regimes during these events.