Role of 'Sea Ice Conveyor' in Arctic Liquid Freshwater Changes

Sam Cornish, University of Oxford, Earth Sciences, Oxford, United Kingdom, Helen Johnson, University of Oxford, Oxford, United Kingdom and Yavor Kostov, University of Exeter, Exeter, United Kingdom
The freshwater content of the Arctic Ocean is intimately linked to the strength of the stratification—a physical characteristic of the Arctic Ocean with wide relevance for climate and biology. Here, we test our hypothesis that wind-driven sea-ice export may play an important role in liquid freshwater variability in the Arctic. The idea rests on the fact that the growth-rate of sea ice is inversely proportional to its thickness. Export of sea ice from the Arctic in winter exposes new areas of ocean to the cold atmosphere—areas where sea-ice should grow comparatively rapidly, drawing freshwater from the liquid reservoir into the solid reservoir. If the winds are sustained, this new sea ice can then also be exported. As such, this mechanism may be likened to a sea ice conveyor belt of freshwater from the liquid reservoir to the North Atlantic. We use coupled climate models, forced model perturbation experiments and observations to assess the effect of this sea-ice conveyor mechanism on liquid freshwater changes within the Arctic.