Mass Balance of Multiyear Sea Ice in the Southern Beaufort Sea

Abstract

Abstract : The long-term goals are: 1) Determination of the net growth and melt of multiyear (MY) sea ice during its transit through the southern Beaufort Sea 2) Identification of key regional processes in southern Beaufort Sea affecting MY ice recruitment 3) Improved predictability of the future states of the Arctic ice pack. We have four main scientific objectives: I) Estimation of MY ice volume entrained into the Beaufort Sea from north of Canada The region north of the Canadian Archipelago contains some of the oldest and thickest ice in the Arctic and the amount of this ice imported into the Beaufort Sea has a significant effect on the overall MY ice budget of the Arctic. II) Estimation of rate of thinning of MY ice during transit through southern Beaufort Sea The thickness of MY ice at the end of its westward transit through the Beaufort Sea will have a critical impact on the volume of MY ice recruited from one year to the next and on navigability in the Beaufort and other marginal seas. III) Assessment of contribution of refreezing of meltwater to overall mass balance of MY ice Meltwater created through surface ablation can refreeze if it finds its way underneath the sea ice where the ocean will typically be at the colder freezing point of seawater. This can create ice lenses and false bottoms beneath the sea ice and make a positive, but poorly-understood, contribution to the mass balance IV) Assessment of the role MY ice dispersal in promoting ice loss We speculate that diminished MY ice in the Beaufort Sea may be a consequence of changes in drift patterns. Moreover, if net drift and divergence increase as MY ice extent decreases, this may represent a feedback process that will accelerate the Arctic s trajectory toward a seasonally ice free state.