Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf
The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change. The increased freshwater output from Antarctica is important in determining sea level rise, the fate of Antarctic sea ice and its effect on the Earth's albed...
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Online Access: | https://nrl.northumbria.ac.uk/id/eprint/42413/ https://doi.org/10.1038/nature20825 https://nrl.northumbria.ac.uk/id/eprint/42413/1/Vigorous%20lateral%20export%20of%20the%20meltwater%20outflow%20from%20beneath%20an%20Antarctic%20ice%20shelf.pdf |
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:42413 2023-05-15T13:44:52+02:00 Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf Garabato, Alberto C. Naveira Forryan, Alexander Dutrieux, Pierre Brannigan, Liam Biddle, Louise C. Heywood, Karen J. Jenkins, Adrian Firing, Yvonne L. Kimura, Satoshi 2017-02-09 text https://nrl.northumbria.ac.uk/id/eprint/42413/ https://doi.org/10.1038/nature20825 https://nrl.northumbria.ac.uk/id/eprint/42413/1/Vigorous%20lateral%20export%20of%20the%20meltwater%20outflow%20from%20beneath%20an%20Antarctic%20ice%20shelf.pdf en eng Nature Publishing https://nrl.northumbria.ac.uk/id/eprint/42413/1/Vigorous%20lateral%20export%20of%20the%20meltwater%20outflow%20from%20beneath%20an%20Antarctic%20ice%20shelf.pdf Garabato, Alberto C. Naveira, Forryan, Alexander, Dutrieux, Pierre, Brannigan, Liam, Biddle, Louise C., Heywood, Karen J., Jenkins, Adrian, Firing, Yvonne L. and Kimura, Satoshi (2017) Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf. Nature, 542 (7640). pp. 219-222. ISSN 0028-0836 F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2017 ftunivnorthumb https://doi.org/10.1038/nature20825 2022-09-25T06:11:38Z The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change. The increased freshwater output from Antarctica is important in determining sea level rise, the fate of Antarctic sea ice and its effect on the Earth's albedo, ongoing changes in global deep-ocean ventilation, and the evolution of Southern Ocean ecosystems and carbon cycling. A key uncertainty in assessing and predicting the impacts of Antarctic Ice Sheet melting concerns the vertical distribution of the exported meltwater. This is usually represented by climate-scale models as a near-surface freshwater input to the ocean, yet measurements around Antarctica reveal the meltwater to be concentrated at deeper levels. Here we use observations of the turbulent properties of the meltwater outflows from beneath a rapidly melting Antarctic ice shelf to identify the mechanism responsible for the depth of the meltwater. We show that the initial ascent of the meltwater outflow from the ice shelf cavity triggers a centrifugal overturning instability that grows by extracting kinetic energy from the lateral shear of the background oceanic flow. The instability promotes vigorous lateral export, rapid dilution by turbulent mixing, and finally settling of meltwater at depth. We use an idealized ocean circulation model to show that this mechanism is relevant to a broad spectrum of Antarctic ice shelves. Our findings demonstrate that the mechanism producing meltwater at depth is a dynamically robust feature of Antarctic melting that should be incorporated into climate-scale models. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean Northumbria University, Newcastle: Northumbria Research Link (NRL) Antarctic Southern Ocean The Antarctic Nature 542 7640 219 222 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Garabato, Alberto C. Naveira Forryan, Alexander Dutrieux, Pierre Brannigan, Liam Biddle, Louise C. Heywood, Karen J. Jenkins, Adrian Firing, Yvonne L. Kimura, Satoshi Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
topic_facet |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change. The increased freshwater output from Antarctica is important in determining sea level rise, the fate of Antarctic sea ice and its effect on the Earth's albedo, ongoing changes in global deep-ocean ventilation, and the evolution of Southern Ocean ecosystems and carbon cycling. A key uncertainty in assessing and predicting the impacts of Antarctic Ice Sheet melting concerns the vertical distribution of the exported meltwater. This is usually represented by climate-scale models as a near-surface freshwater input to the ocean, yet measurements around Antarctica reveal the meltwater to be concentrated at deeper levels. Here we use observations of the turbulent properties of the meltwater outflows from beneath a rapidly melting Antarctic ice shelf to identify the mechanism responsible for the depth of the meltwater. We show that the initial ascent of the meltwater outflow from the ice shelf cavity triggers a centrifugal overturning instability that grows by extracting kinetic energy from the lateral shear of the background oceanic flow. The instability promotes vigorous lateral export, rapid dilution by turbulent mixing, and finally settling of meltwater at depth. We use an idealized ocean circulation model to show that this mechanism is relevant to a broad spectrum of Antarctic ice shelves. Our findings demonstrate that the mechanism producing meltwater at depth is a dynamically robust feature of Antarctic melting that should be incorporated into climate-scale models. |
format |
Article in Journal/Newspaper |
author |
Garabato, Alberto C. Naveira Forryan, Alexander Dutrieux, Pierre Brannigan, Liam Biddle, Louise C. Heywood, Karen J. Jenkins, Adrian Firing, Yvonne L. Kimura, Satoshi |
author_facet |
Garabato, Alberto C. Naveira Forryan, Alexander Dutrieux, Pierre Brannigan, Liam Biddle, Louise C. Heywood, Karen J. Jenkins, Adrian Firing, Yvonne L. Kimura, Satoshi |
author_sort |
Garabato, Alberto C. Naveira |
title |
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
title_short |
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
title_full |
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
title_fullStr |
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
title_full_unstemmed |
Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf |
title_sort |
vigorous lateral export of the meltwater outflow from beneath an antarctic ice shelf |
publisher |
Nature Publishing |
publishDate |
2017 |
url |
https://nrl.northumbria.ac.uk/id/eprint/42413/ https://doi.org/10.1038/nature20825 https://nrl.northumbria.ac.uk/id/eprint/42413/1/Vigorous%20lateral%20export%20of%20the%20meltwater%20outflow%20from%20beneath%20an%20Antarctic%20ice%20shelf.pdf |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/42413/1/Vigorous%20lateral%20export%20of%20the%20meltwater%20outflow%20from%20beneath%20an%20Antarctic%20ice%20shelf.pdf Garabato, Alberto C. Naveira, Forryan, Alexander, Dutrieux, Pierre, Brannigan, Liam, Biddle, Louise C., Heywood, Karen J., Jenkins, Adrian, Firing, Yvonne L. and Kimura, Satoshi (2017) Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf. Nature, 542 (7640). pp. 219-222. ISSN 0028-0836 |
op_doi |
https://doi.org/10.1038/nature20825 |
container_title |
Nature |
container_volume |
542 |
container_issue |
7640 |
container_start_page |
219 |
op_container_end_page |
222 |
_version_ |
1766207776669827072 |