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: |
2018
|
Subjects: | |
Online Access: | https://eprints.soton.ac.uk/469726/ |
id |
ftsouthampton:oai:eprints.soton.ac.uk:469726 |
---|---|
record_format |
openpolar |
spelling |
ftsouthampton:oai:eprints.soton.ac.uk:469726 2023-07-30T03:56:03+02:00 Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic bottom water Silvano, Alessandro Rintoul, Stephen Rich Peña-Molino, Beatriz Hobbs, William Richard Wijk, Esmee van Aoki, Shigeru Tamura, Takeshi Williams, Guy Darvall 2018-04-18 https://eprints.soton.ac.uk/469726/ English eng Silvano, Alessandro, Rintoul, Stephen Rich, Peña-Molino, Beatriz, Hobbs, William Richard, Wijk, Esmee van, Aoki, Shigeru, Tamura, Takeshi and Williams, Guy Darvall (2018) Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic bottom water. Science Advances, 4 (4). (doi:10.1126/sciadv.aap9467 <http://dx.doi.org/10.1126/sciadv.aap9467>). Article PeerReviewed 2018 ftsouthampton https://doi.org/10.1126/sciadv.aap9467 2023-07-09T22:55:06Z 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 Southampton: e-Prints Soton 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 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
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, Alessandro Rintoul, Stephen Rich Peña-Molino, Beatriz Hobbs, William Richard Wijk, Esmee van Aoki, Shigeru Tamura, Takeshi Williams, Guy Darvall |
spellingShingle |
Silvano, Alessandro Rintoul, Stephen Rich Peña-Molino, Beatriz Hobbs, William Richard Wijk, Esmee van Aoki, Shigeru Tamura, Takeshi Williams, Guy Darvall Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic bottom water |
author_facet |
Silvano, Alessandro Rintoul, Stephen Rich Peña-Molino, Beatriz Hobbs, William Richard Wijk, Esmee van Aoki, Shigeru Tamura, Takeshi Williams, Guy Darvall |
author_sort |
Silvano, Alessandro |
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 |
publishDate |
2018 |
url |
https://eprints.soton.ac.uk/469726/ |
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 |
Silvano, Alessandro, Rintoul, Stephen Rich, Peña-Molino, Beatriz, Hobbs, William Richard, Wijk, Esmee van, Aoki, Shigeru, Tamura, Takeshi and Williams, Guy Darvall (2018) Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic bottom water. Science Advances, 4 (4). (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 |
_version_ |
1772810777525223424 |