Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica
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 Circump...
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ftcopernicus:oai:publications.copernicus.org:tcd88740 2023-05-15T13:31:39+02:00 Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica Kusahara, Kazuya Hirano, Daisuke Fujii, Masakazu Fraser, Alexander D. Tamura, Takeshi 2020-08-27 application/pdf https://doi.org/10.5194/tc-2020-240 https://tc.copernicus.org/preprints/tc-2020-240/ eng eng doi:10.5194/tc-2020-240 https://tc.copernicus.org/preprints/tc-2020-240/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-2020-240 2020-08-31T16:22:12Z 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. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Shirase Glacier Totten Ice Shelf Copernicus Publications: E-Journals Antarctic East Antarctica Lützow-Holm Bay ENVELOPE(38.000,38.000,-69.500,-69.500) Shirase Glacier ENVELOPE(39.000,39.000,-70.333,-70.333) The Antarctic Weddell |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
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. |
format |
Text |
author |
Kusahara, Kazuya Hirano, Daisuke Fujii, Masakazu Fraser, Alexander D. Tamura, Takeshi |
spellingShingle |
Kusahara, Kazuya Hirano, Daisuke Fujii, Masakazu Fraser, Alexander D. Tamura, Takeshi Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
author_facet |
Kusahara, Kazuya Hirano, Daisuke Fujii, Masakazu Fraser, Alexander D. Tamura, Takeshi |
author_sort |
Kusahara, Kazuya |
title |
Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
title_short |
Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
title_full |
Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
title_fullStr |
Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
title_full_unstemmed |
Modeling intensive ocean–cryosphere interactions in Lützow-Holm Bay, East Antarctica |
title_sort |
modeling intensive ocean–cryosphere interactions in lützow-holm bay, east antarctica |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-2020-240 https://tc.copernicus.org/preprints/tc-2020-240/ |
long_lat |
ENVELOPE(38.000,38.000,-69.500,-69.500) ENVELOPE(39.000,39.000,-70.333,-70.333) |
geographic |
Antarctic East Antarctica Lützow-Holm Bay Shirase Glacier The Antarctic Weddell |
geographic_facet |
Antarctic East Antarctica Lützow-Holm Bay Shirase Glacier The Antarctic Weddell |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Shirase Glacier Totten Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Shirase Glacier Totten Ice Shelf |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2020-240 https://tc.copernicus.org/preprints/tc-2020-240/ |
op_doi |
https://doi.org/10.5194/tc-2020-240 |
_version_ |
1766019676844851200 |