Whither the Chukchi Slope Current?

Thomas Peacock1, Samuel Boury2, Philippe Odier3, Robert S Pickart4, Peigen Lin4, Min Li5, Elizabeth Fine6 and Jennifer A MacKinnon6, (1)Massachusetts Institute of Technology, Cambridge, MA, United States, (2)ENS de Lyon, France, (3)Ecole Normale Supérieure de Lyon, Laboratoire de Physique, Lyon, France, (4)Woods Hole Oceanographic Institution, Woods Hole, MA, United States, (5)Guandong Ocean University, China, (6)Scripps Institution of Oceanography, La Jolla, CA, United States
Abstract:
Identifying the pathways and mechanisms by which Pacific-origin water enters the deep Arctic Basin via the

Chukchi Shelf is of great interest for improving our understanding of the evolving state of the Arctic Ocean.

This includes the seasonal-to-interannual variation of the pack-ice, as well as the maintenance of the Beaufort

Gyre freshwater reservoir. In this study we use a combination of late-summer shipboard measurements and

profiling Lagrangian float trajectories to investigate the path and fate of the newly discovered Chukchi Slope

Current (CSC), which is believed to account for most of the Pacific water outflow from the shelf through Barrow

Canyon. During the measurement period the CSC was a well-defined feature transporting warm and fresh water

toward ice-covered regions. The current was abruptly diverted to the North into the Chukchi Borderland region,

as opposed to continuing eastward along the upper continental slope. This suggests that, at times, the current

can become entrained into the Beaufort Gyre. We demonstrate that the transport of the CSC is impacted by

wind forcing that can strengthen, retard, or reverse the flow. It also appears that the CSC can get disrupted

by eddy-current interactions, leading to mixing with cold, ambient basin water that reduces the heat content of

the current.