Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water
Strong heat loss and brine release during sea ice formation in coastal polynyas act to cool and salinify waters on the Antarctic continental shelf. Polynya activity thus both limits the ocean heat flux to the Antarctic Ice Sheet and promotes formation of Dense Shelf Water (DSW), the precursor to Ant...
Published in: | Science Advances |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Association for the Advancement of Science (A A A S)
2018
|
Subjects: | |
Online Access: | https://eprints.utas.edu.au/26429/ https://eprints.utas.edu.au/26429/1/125485%20final.pdf |
id |
ftunivtasmania:oai:eprints.utas.edu.au:26429 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasmania:oai:eprints.utas.edu.au:26429 2023-05-15T13:23:53+02:00 Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water Silvano, A Rintoul, SR Pena-Molino, B Hobbs, WR van Wijk, E Aoki, S Tamura, T Williams, GD 2018 application/pdf https://eprints.utas.edu.au/26429/ https://eprints.utas.edu.au/26429/1/125485%20final.pdf en eng American Association for the Advancement of Science (A A A S) https://eprints.utas.edu.au/26429/1/125485%20final.pdf Silvano, A, Rintoul, SR orcid:0000-0002-7055-9876 , Pena-Molino, B orcid:0000-0003-1587-1696 , Hobbs, WR orcid:0000-0002-2061-0899 , van Wijk, E, Aoki, S, Tamura, T and Williams, GD orcid:0000-0003-1769-8356 2018 , 'Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water' , Science Advances, vol. 4, no. 4 , pp. 1-12 , doi:10.1126/sciadv.aap9467 <http://dx.doi.org/10.1126/sciadv.aap9467>. Antarctic oceanography ocean-ice shelf interaction Article PeerReviewed 2018 ftunivtasmania https://doi.org/10.1126/sciadv.aap9467 2021-09-20T22:16:35Z Strong heat loss and brine release during sea ice formation in coastal polynyas act to cool and salinify waters on the Antarctic continental shelf. Polynya activity thus both limits the ocean heat flux to the Antarctic Ice Sheet and promotes formation of Dense Shelf Water (DSW), the precursor to Antarctic Bottom Water. However, despite the presence of strong polynyas, DSW is not formed on the Sabrina Coast in East Antarctica and in the Amundsen Sea in West Antarctica. Using a simple ocean model driven by observed forcing, we show that freshwater input from basal melt of ice shelves partially offsets the salt flux by sea ice formation in polynyas found in both regions, preventing full-depth convection and formation of DSW. In the absence of deep convection, warm water that reaches the continental shelf in the bottom layer does not lose much heat to the atmosphere and is thus available to drive the rapid basal melt observed at the Totten Ice Shelf on the Sabrina Coast and at the Dotson and Getz ice shelves in the Amundsen Sea. Our results suggest that increased glacial meltwater input in a warming climate will both reduce Antarctic Bottom Water formation and trigger increased mass loss from the Antarctic Ice Sheet, with consequences for the global overturning circulation and sea level rise. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Totten Ice Shelf West Antarctica University of Tasmania: UTas ePrints Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) Sabrina Coast ENVELOPE(118.550,118.550,-67.000,-67.000) Science Advances 4 4 eaap9467 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
Antarctic oceanography ocean-ice shelf interaction |
spellingShingle |
Antarctic oceanography ocean-ice shelf interaction Silvano, A Rintoul, SR Pena-Molino, B Hobbs, WR van Wijk, E Aoki, S Tamura, T Williams, GD Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
topic_facet |
Antarctic oceanography ocean-ice shelf interaction |
description |
Strong heat loss and brine release during sea ice formation in coastal polynyas act to cool and salinify waters on the Antarctic continental shelf. Polynya activity thus both limits the ocean heat flux to the Antarctic Ice Sheet and promotes formation of Dense Shelf Water (DSW), the precursor to Antarctic Bottom Water. However, despite the presence of strong polynyas, DSW is not formed on the Sabrina Coast in East Antarctica and in the Amundsen Sea in West Antarctica. Using a simple ocean model driven by observed forcing, we show that freshwater input from basal melt of ice shelves partially offsets the salt flux by sea ice formation in polynyas found in both regions, preventing full-depth convection and formation of DSW. In the absence of deep convection, warm water that reaches the continental shelf in the bottom layer does not lose much heat to the atmosphere and is thus available to drive the rapid basal melt observed at the Totten Ice Shelf on the Sabrina Coast and at the Dotson and Getz ice shelves in the Amundsen Sea. Our results suggest that increased glacial meltwater input in a warming climate will both reduce Antarctic Bottom Water formation and trigger increased mass loss from the Antarctic Ice Sheet, with consequences for the global overturning circulation and sea level rise. |
format |
Article in Journal/Newspaper |
author |
Silvano, A Rintoul, SR Pena-Molino, B Hobbs, WR van Wijk, E Aoki, S Tamura, T Williams, GD |
author_facet |
Silvano, A Rintoul, SR Pena-Molino, B Hobbs, WR van Wijk, E Aoki, S Tamura, T Williams, GD |
author_sort |
Silvano, A |
title |
Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
title_short |
Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
title_full |
Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
title_fullStr |
Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
title_full_unstemmed |
Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water |
title_sort |
freshening by glacial meltwater enhances melting of ice shelves and reduces formation of antarctic bottom water |
publisher |
American Association for the Advancement of Science (A A A S) |
publishDate |
2018 |
url |
https://eprints.utas.edu.au/26429/ https://eprints.utas.edu.au/26429/1/125485%20final.pdf |
long_lat |
ENVELOPE(-145.217,-145.217,-76.550,-76.550) ENVELOPE(118.550,118.550,-67.000,-67.000) |
geographic |
Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea Getz Sabrina Coast |
geographic_facet |
Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea Getz Sabrina Coast |
genre |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Totten Ice Shelf West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Totten Ice Shelf West Antarctica |
op_relation |
https://eprints.utas.edu.au/26429/1/125485%20final.pdf Silvano, A, Rintoul, SR orcid:0000-0002-7055-9876 , Pena-Molino, B orcid:0000-0003-1587-1696 , Hobbs, WR orcid:0000-0002-2061-0899 , van Wijk, E, Aoki, S, Tamura, T and Williams, GD orcid:0000-0003-1769-8356 2018 , 'Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water' , Science Advances, vol. 4, no. 4 , pp. 1-12 , doi:10.1126/sciadv.aap9467 <http://dx.doi.org/10.1126/sciadv.aap9467>. |
op_doi |
https://doi.org/10.1126/sciadv.aap9467 |
container_title |
Science Advances |
container_volume |
4 |
container_issue |
4 |
container_start_page |
eaap9467 |
_version_ |
1766376046260649984 |