Eddy-mediated transport of warm Circumpolar Deep Water across the Antarctic Shelf Break
The Antarctic Slope Front (ASF) modulates ventilation of the abyssal ocean via the export of dense Antarctic Bottom Water (AABW) and constrains shoreward transport of warm Circumpolar Deep Water (CDW) toward marine-terminating glaciers. Along certain stretches of the continental shelf, particularly where AABW is exported, density surfaces connect the shelf waters to the middepth Circumpolar Deep Water offshore, offering a pathway for mesoscale eddies to transport CDW directly onto the continental shelf. Using an eddy-resolving process model of the ASF, the authors show that mesoscale eddies can supply a dynamically significant transport of heat and mass across the continental shelf break. The shoreward transport of surface waters is purely wind driven, while the shoreward CDW transport is entirely due to mesoscale eddy transfer. The CDW flux is sensitive to all aspects of the model's surface forcing and geometry, suggesting that shoreward eddy heat transport may be localized to favorable sections of the continental slope.
© 2014 American Geophysical Union. Received 21 OCT 2014; Accepted 17 DEC 2014; Accepted article online 19 DEC 2014; Published online 22 JAN 2015. A.L.S.'s and A.F.T.'s research was funded by NSF award OPP-124646, and under a contract with the National Aeronautics and Space Administration, funded through the President's and Director's Fund Program. The simulations presented herein were conducted using the CITerra computing cluster in the Division of Geological and Planetary Sciences at the California Institute of Technology, and the authors thank the CITerra technicians for facilitating this work. The data presented in this article are available from the authors on request. The authors gratefully acknowledge the modeling efforts of the MITgcm team. The authors thank Karen Assman and another anonymous reviewer for constructive comments that improved this paper.
Supplemental Material - grl52475-sup-0001-supplementary.pdf