Deep mesoscale eddies in the Canada Basin, Arctic Ocean

Abstract

Numerous eddies have been identified in a seven year time series of mooring observations in the Canada Basin, Arctic Ocean. We focus on a series of deep eddies centered at ∼1200 m depth, and occupying up to 1500 m of the water column. The deep eddies are found to be spatially localized, only ever being observed at one of four mooring sites of the Beaufort Gyre Observing System in the Canada Basin. However, despite only a few previously reported observations of deep eddies in the Arctic Ocean, we find that they are the most prevalent eddy-type at this location. Based on this observation, together with an analysis of the temperature-salinity structure, and the exclusively anticyclonic rotation of the deep eddies, we hypothesize that they are formed by a density-driven outflow from the Chukchi Borderland region. We also describe a simple analytical model to explain the observed vertical scales of the eddies. © 2012. American Geophysical Union. All Rights Reserved.