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Modeling intensive ocean-cryosphere interactions in Lützow-Holm Bay, East Antarctica

Citation

Kusahara, K and Hirano, D and Fujii, M and Fraser, AD and Tamura, T, Modeling intensive ocean-cryosphere interactions in Lutzow-Holm Bay, East Antarctica, Cryosphere, 15 pp. 1697-1717. ISSN 1994-0416 (2021) [Refereed Article]


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Copyright Statement

Copyright the Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License

DOI: doi:10.5194/tc-2020-240

Abstract

Basal melting of Antarctic ice shelves accounts for more than half of the mass loss from the Antarctic Ice Sheet. Many studies have focused on active basal melting at ice shelves in the Amundsen-Bellingshausen Seas and the Totten Ice shelf, East Antarctica. In these regions, the intrusion of Circumpolar Deep Water (CDW) onto the continental shelf is a key component for the localized intensive basal melting. Both regions have a common oceanographic feature: southward deflection of the Antarctic Circumpolar Current on the eastern flank of ocean gyres brings CDW onto the continental shelves. The physical setting of Shirase Glacier Tongue (SGT) in Lützow-Holm Bay corresponds to a similar configuration for the Weddell Gyre in the Atlantic sector. Here, we conduct a 2–3 km resolution simulation of an ocean-sea ice-ice shelf model using a newly-compiled bottom topography dataset in the bay. The model can reproduce the observed CDW intrusion along the deep trough. The modeled SGT basal melting reaches a peak in summer and minimum in autumn and winter, consistent with the wind-driven seasonality of the CDW thickness in the bay. The model results suggest the existence of eastward-flowing undercurrent on the upper continental slope in summer, and the undercurrent contributes to the seasonal-to-interannual variability of the warm water intrusion into the bay. Furthermore, numerical experiments with and without fast-ice cover in the bay demonstrate that fast ice plays a role as an effective thermal insulator and reduces local sea-ice formation, resulting in much warmer water intrusion into the SGT cavity.

Item Details

Item Type:Refereed Article
Keywords:Antarctic oceanography, water mass modification
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical oceanography
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Understanding climate change
Objective Field:Climate variability (excl. social impacts)
UTAS Author:Fraser, AD (Dr Alex Fraser)
ID Code:143516
Year Published:2021
Web of Science® Times Cited:1
Deposited By:Australian Antarctic Program Partnership
Deposited On:2021-03-22
Last Modified:2021-10-11
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