The Chukchi slope current

• Published in: Progress in Oceanography
• Main Authors: Corlett, W. Bryce, Pickart, Robert S.
• Format: Report
• Language: English
• Published: 2017
• Subjects: Arctic Ocean; Chukchi Sea; Shelfbreak; Mass budget; Arctic; Pacific; Chukchi Shelf; Barrow Canyon; Chukchi
• Online Access: https://hdl.handle.net/1912/9054

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Progress in Oceanography 153 (2017): 50-65, doi:10.1016/j.pocean.2017.04.005. Using a collection of 46 shipboard hydrographic/velocity transects occupied across the shelfbreak and slope of the Chukchi Sea between 2002 and 2014, we have quantified the existence of a current transporting Pacific-origin water westward over the upper continental slope. It has been named the Chukchi slope current, which is believed to emanate from Barrow Canyon. The current is surface-intensified, order 50 km wide, and advects both summer and winter waters. It is not trapped to a particular isobath, but instead is reminiscent of a free jet. There is no significant variation in Pacific water transport with distance from Barrow Canyon. A potential vorticity analysis suggests that the flow is baroclinically unstable, consistent with the notion that it meanders. The current is present during all synoptic wind conditions, but increases in strength from summer to fall presumably due to the seasonal enhancement of the easterly winds in the region. Its transport increased over the 12-year period of data coverage, also likely in response to wind forcing. In the mean, the slope current transports 0.50±0.070.50±0.07 Sv of Pacific water. This estimate allows us to construct a balanced mass budget of the Chukchi shelf inflows and outflows. Our study also confirms the existence of an eastward-flowing Chukchi shelfbreak jet transporting 0.10±0.030.10±0.03 Sv of Pacific water towards Barrow Canyon. This work was funded under contract M12AC00008 from the Bureau of Ocean and Energy Management.