The Water Masses Advections in the Arctic Ocean Over the Past Ten Years

The Arctic Ocean is subjected to oceanic advections which influence its heat and salt balance. This affects in turn the water column stratification and thus the halocline, a very important physical characteristics of the Arctic Ocean. The warm and relatively fresh waters entering the Arctic Ocean by Bering Strait weaken the water column stratification at shallow depth, while the warm and salty Atlantic origin waters entering by Fram Strait or the Barents Sea influence the water column stratification at greater depth (300 meters). Therefore, the study of these water masses circulation and distribution is of first importance for a better understanding of the Arctic Ocean. During the 1990's, changes in the spatial distribution of these waters as well as in their core temperature were observed (Quadfasel 1991, McLaughlin 1996). Today, what is the situation? How did these water masses evolve during the last ten years? Here, we present indices created in order to quantify the influence of the Atlantic water (AWI for Atlantic Water Index) and the influence of the Summer Pacific water (PWI for summer Pacific Water Index).