Export and circulation of ice cavity water in Pine Island Bay, West Antarctica

Thurnherr, A. M.; Jacobs, S. S.; Dutrieux, P. ORCID: https://orcid.org/0000-0002-8066-934X; Giulivi, C. F.. 2014 Export and circulation of ice cavity water in Pine Island Bay, West Antarctica. Journal of Geophysical Research: Oceans, 119 (3). 1754-1764. https://doi.org/10.1002/2013JC009307

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Official URL: http://dx.doi.org/10.1002/2013JC009307

Abstract/Summary

Large sectors of the Antarctic ice sheet are vulnerable to increases in melting at the bases of fringing ice shelves, with melt rates depending on ocean temperatures and circulations in the sub-ice cavities. Here we analyze an oceanographic data set obtained in austral summer 2009 in Pine Island Bay, which is bounded in the east by the calving front of the Amundsen Sea's fast-moving Pine Island Ice Shelf. The upper-ocean velocity field in the ice-free bay was dominated by a 700 m deep and 50 km wide gyre circulating 1.5 Sv of water clockwise around the bay. Ice cavity water was observed in a surface-intensified and southward-intensified boundary current along the ice front, and in a small ice cove at the end of the southern shear margin of the ice shelf. Repeat measurements in the cove reveal persistent cavity water export of ≈ 0.25 Sv during 10 days of sampling. Vertical velocities in the cove above the ice draft were dominated by buoyancy-frequency oscillations with amplitudes of several cm/s but without significant net upwelling. In combination with the seawater properties, this observation indicates that much of the upwelling occurs within fractured ice near the cove, potentially contributing to weakening the ice shelf shear margin.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1002/2013JC009307
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Polar Oceans
ISSN:	21699275
Additional Keywords:	Pine Island Bay
Date made live:	24 Jun 2014 10:40 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/507555

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1002/2013JC009307

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Polar Oceans

ISSN:

21699275

Additional Keywords:

Pine Island Bay

Date made live:

24 Jun 2014 10:40 +0 (UTC)