The impact of overturning and horizontal circulation in Pine Island Trough on ice shelf melt in the eastern Amundsen Sea

Webber, Benjamin, Heywood, Karen, Stevens, David and Assmann, Karen (2019) The impact of overturning and horizontal circulation in Pine Island Trough on ice shelf melt in the eastern Amundsen Sea. Journal of Physical Oceanography, 49 (1). pp. 63-83. ISSN 0022-3670

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      Abstract

      The ice shelves around the Amundsen Sea are rapidly melting due to circulation of relatively warm ocean water into their cavities. However, little is known about the processes that determine the variability of this circulation. Here we use an ocean circulation model to diagnose the relative importance of horizontal and vertical (overturning) circulation within Pine Island Trough, leading to Pine Island and Thwaites ice shelves. We show that melt rates and southward CDW transports co-vary over large parts of the continental shelf at interannual to decadal time scales. The dominant external forcing mechanism for this variability is Ekman pumping and suction on the continental shelf and at the shelf break, in agreement with previous studies. At the continental shelf break, the southward transport of CDWand heat is predominantly barotropic. Further south within Pine Island Trough, northward and southward barotropic heat transports largely cancel and the majority of the net southward temperature transport is facilitated by baroclinic and overturning circulations. The overturning circulation is related to water mass transformation and buoyancy gain on the shelf that is primarily facilitated by freshwater input from basal melting.

      Item Type: Article
      Faculty \ School: Faculty of Science > School of Environmental Sciences
      Faculty of Science > School of Mathematics
      Depositing User: LivePure Connector
      Date Deposited: 02 Nov 2018 17:30
      Last Modified: 10 Feb 2019 20:30
      URI: https://ueaeprints.uea.ac.uk/id/eprint/68755
      DOI: 10.1175/JPO-D-17-0213.1

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