Impact of West Antarctic ice shelf melting on Southern Ocean hydrography
Previous studies show accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were previously small and increased in the middle of the 20th century. This enhanced melting is a likely source of the observed Ross Sea (RS) freshening, but its long-term impact on the S...
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ftcopernicus:oai:publications.copernicus.org:tc80885 2023-05-15T13:55:28+02:00 Impact of West Antarctic ice shelf melting on Southern Ocean hydrography Nakayama, Yoshihiro Timmermann, Ralph H. Hellmer, Hartmut 2020-07-13 application/pdf https://doi.org/10.5194/tc-14-2205-2020 https://tc.copernicus.org/articles/14/2205/2020/ eng eng doi:10.5194/tc-14-2205-2020 https://tc.copernicus.org/articles/14/2205/2020/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-14-2205-2020 2020-07-20T16:22:00Z Previous studies show accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were previously small and increased in the middle of the 20th century. This enhanced melting is a likely source of the observed Ross Sea (RS) freshening, but its long-term impact on the Southern Ocean hydrography has not been well investigated. Here, we conduct coupled sea ice–ice shelf–ocean simulations with different levels of ice shelf melting from West Antarctic glaciers. Freshening of RS shelf and bottom water is simulated with enhanced West Antarctic ice shelf melting, while no significant changes in shelf water properties are simulated when West Antarctic ice shelf melting is small. We further show that the freshening caused by glacial meltwater from ice shelves in the Amundsen and Bellingshausen seas can propagate further downstream along the East Antarctic coast into the Weddell Sea. The freshening signal propagates onto the RS continental shelf within a year of model simulation, while it takes roughly 5–10 and 10–15 years to propagate into the region off Cape Darnley and into the Weddell Sea, respectively. This advection of freshening modulates the shelf water properties and possibly impacts the production of Antarctic Bottom Water if the enhanced melting of West Antarctic ice shelves continues for a longer period. Text Antarc* Antarctic Ice Shelf Ice Shelves Ross Sea Sea ice Southern Ocean Weddell Sea Copernicus Publications: E-Journals Antarctic Cape Darnley ENVELOPE(69.567,69.567,-67.738,-67.738) Darnley ENVELOPE(69.717,69.717,-67.717,-67.717) Ross Sea Southern Ocean Weddell Weddell Sea The Cryosphere 14 7 2205 2216 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Previous studies show accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were previously small and increased in the middle of the 20th century. This enhanced melting is a likely source of the observed Ross Sea (RS) freshening, but its long-term impact on the Southern Ocean hydrography has not been well investigated. Here, we conduct coupled sea ice–ice shelf–ocean simulations with different levels of ice shelf melting from West Antarctic glaciers. Freshening of RS shelf and bottom water is simulated with enhanced West Antarctic ice shelf melting, while no significant changes in shelf water properties are simulated when West Antarctic ice shelf melting is small. We further show that the freshening caused by glacial meltwater from ice shelves in the Amundsen and Bellingshausen seas can propagate further downstream along the East Antarctic coast into the Weddell Sea. The freshening signal propagates onto the RS continental shelf within a year of model simulation, while it takes roughly 5–10 and 10–15 years to propagate into the region off Cape Darnley and into the Weddell Sea, respectively. This advection of freshening modulates the shelf water properties and possibly impacts the production of Antarctic Bottom Water if the enhanced melting of West Antarctic ice shelves continues for a longer period. |
format |
Text |
author |
Nakayama, Yoshihiro Timmermann, Ralph H. Hellmer, Hartmut |
spellingShingle |
Nakayama, Yoshihiro Timmermann, Ralph H. Hellmer, Hartmut Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
author_facet |
Nakayama, Yoshihiro Timmermann, Ralph H. Hellmer, Hartmut |
author_sort |
Nakayama, Yoshihiro |
title |
Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
title_short |
Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
title_full |
Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
title_fullStr |
Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
title_full_unstemmed |
Impact of West Antarctic ice shelf melting on Southern Ocean hydrography |
title_sort |
impact of west antarctic ice shelf melting on southern ocean hydrography |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-2205-2020 https://tc.copernicus.org/articles/14/2205/2020/ |
long_lat |
ENVELOPE(69.567,69.567,-67.738,-67.738) ENVELOPE(69.717,69.717,-67.717,-67.717) |
geographic |
Antarctic Cape Darnley Darnley Ross Sea Southern Ocean Weddell Weddell Sea |
geographic_facet |
Antarctic Cape Darnley Darnley Ross Sea Southern Ocean Weddell Weddell Sea |
genre |
Antarc* Antarctic Ice Shelf Ice Shelves Ross Sea Sea ice Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Ice Shelf Ice Shelves Ross Sea Sea ice Southern Ocean Weddell Sea |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-14-2205-2020 https://tc.copernicus.org/articles/14/2205/2020/ |
op_doi |
https://doi.org/10.5194/tc-14-2205-2020 |
container_title |
The Cryosphere |
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14 |
container_issue |
7 |
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2205 |
op_container_end_page |
2216 |
_version_ |
1766262083340468224 |