Genesis of the Antarctic Slope Current in West Antarctica

The stability of the West Antarctic Ice Sheet (WAIS) depends on ocean heat transport toward its base and remains a source of uncertainty in sea level rise prediction. The Antarctic Slope Current (ASC), a major boundary current of the ocean's global circulation, serves as a dynamic gateway for h...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Thompson, Andrew F., Speer, Kevin G., Schulze Chretien, Lena M.
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2020
Subjects:
Online Access:https://authors.library.caltech.edu/105002/
https://authors.library.caltech.edu/105002/1/2020GL087802.pdf
https://authors.library.caltech.edu/105002/3/grl60853-sup-0001-2020gl087802-figure_si-s01.pdf
https://resolver.caltech.edu/CaltechAUTHORS:20200818-125233247
Description
Summary:The stability of the West Antarctic Ice Sheet (WAIS) depends on ocean heat transport toward its base and remains a source of uncertainty in sea level rise prediction. The Antarctic Slope Current (ASC), a major boundary current of the ocean's global circulation, serves as a dynamic gateway for heat transport toward Antarctica. Here, we use observations collected from the Bellingshausen Sea to propose a mechanistic explanation for the initiation of the westward‐flowing ASC. Waters modified throughout the Bellingshausen Sea by ocean‐sea‐ice and ocean‐ice‐shelf interactions are exported to the continental slope in a narrow, topographically steered western boundary current. This focused outflow produces a localized front at the shelf break that supports the emerging ASC. This mechanism emphasizes the importance of buoyancy forcing, integrated over the continental shelf, as opposed to local wind forcing, in the generation mechanism and suggests the potential for remote control of melt rates of WAIS' largest ice shelves.