Models and palaeoceanographic data show that increased freshwater input from the Arctic to the North Atlantic can "distress" the thermohaline circulation. A decrease in the North Atlantic overturning may lead to a cooling of Northern Europe, so the understanding of these changes is one of the highest priorities for UK and NERC science. However our understanding of the mechanisms by which the freshwater input to the Arctic is transformed, stored, and exported is currently based on fragmentary observations, and poorly constrained models.

By combining the data gathered during IPY with historical and satellite data, our programme will use state-of-the- art numerical models to provide new quantitative estimates of the storage and transport of fresh water in the Arctic both for the present, recent past and next century.