Variability of Arctic fresh water and its impact on the North Atlantic Ocean

Arctic ocean halocline and sea ice together establish a reservoir of fresh water that can sustain decadal scale anomalies of fresh water export to lower latitudes. We will present ocean-sea ice model results from hindcasts forced by NCEP reanalysis data that indicate a decline of the Arctic fresh water reservoir from the mid-1960s onward. This is achieved by an imbalance in the fresh water supply and export through Fram Strait, the Barents Sea opening and the Canadian Archipelago.

A long term trend is sumperimposed by several fresh water export events. We will discuss the origin of variability in the fresh water reservoir and the export. The pathways and travel times of the Arctic fresh water into the Arctic and subarctic North Atlantic will be presented. The impact of the fresh water on the horizontal and overturning motion in the North Atlantic will be discussed in comparison to the effects of other forcing components.