The role of the Beaufort Gyre in the Arctic climate system changes

The Arctic climate is undergoing major changes. In the summer of 2007, sea-ice extent reached a record minimum, including severe loss in the Arctic's Beaufort Gyre, an ice-ocean circulation system in the Canadian Basin. Furthermore, observations in the Beaufort Gyre during the past decade reveal a dramatic warming and freshening of the ocean. These changes are caused by a complex balance of local and global factors that may include enhanced ice melt, increased solar absorption in the surface ocean, changes in precipitation, and warmer Pacific and Atlantic origin source waters, although the distinct mechanisms and feedbacks are uncertain. Moreover, it is unclear why the most prominent Arctic changes are occurring in the Beaufort Gyre region; nor is it understood how processes there can impact the entire Arctic, and global climate. Beaufort Gyre dynamics and thermodynamics remain an important, unresolved aspect of the climate system. We report results of our investigation of causes and consequences of the unprecedented ocean heat and freshwater changes in the Beaufort Gyre. Several observational and dynamical questions will be addressed: How does the declining ice cover relate to changes in ocean heat and fresh water? How do the surface, Pacific and Atlantic waters contribute to the heat and fresh-water balance and change in the Beaufort Gyre? To what extent are recent warming and freshening signals stored in the ocean, both seasonally and interannually? How much heat is transported from deeper waters to the ocean surface and ice cover?