The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet
The Amundsen Sea has the highest thinning rates of ice shelves in Antarctica. This imbalance is caused by changes in ocean melting induced by warm Circumpolar Deep Water (CDW) intrusions. The resulting changing freshwater balance could affect the on‐shelf currents and mixing. However, a clear unders...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2020
|
Subjects: | |
Online Access: | https://nrl.northumbria.ac.uk/id/eprint/45295/ https://doi.org/10.1029/2020jc016305 https://nrl.northumbria.ac.uk/id/eprint/45295/1/2020JC016305.pdf |
id |
ftunivnorthumb:oai:nrl.northumbria.ac.uk:45295 |
---|---|
record_format |
openpolar |
spelling |
ftunivnorthumb:oai:nrl.northumbria.ac.uk:45295 2023-05-15T13:23:47+02:00 The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet Bett, David T. Holland, Paul R. Naveira Garabato, Alberto C. Jenkins, Adrian Dutrieux, Pierre Kimura, Satoshi Fleming, Andrew 2020-09 text https://nrl.northumbria.ac.uk/id/eprint/45295/ https://doi.org/10.1029/2020jc016305 https://nrl.northumbria.ac.uk/id/eprint/45295/1/2020JC016305.pdf en eng American Geophysical Union https://nrl.northumbria.ac.uk/id/eprint/45295/1/2020JC016305.pdf Bett, David T., Holland, Paul R., Naveira Garabato, Alberto C., Jenkins, Adrian, Dutrieux, Pierre, Kimura, Satoshi and Fleming, Andrew (2020) The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet. Journal of Geophysical Research: Oceans, 125 (9). ISSN 2169-9275 cc_by_4_0 CC-BY F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences F900 Others in Physical Sciences Article PeerReviewed 2020 ftunivnorthumb https://doi.org/10.1029/2020jc016305 2022-09-25T06:13:18Z The Amundsen Sea has the highest thinning rates of ice shelves in Antarctica. This imbalance is caused by changes in ocean melting induced by warm Circumpolar Deep Water (CDW) intrusions. The resulting changing freshwater balance could affect the on‐shelf currents and mixing. However, a clear understanding of the sources and sinks of freshwater in the region is lacking. Here we use a model of the Amundsen Sea, with passive freshwater tracers, to investigate the relative magnitudes and spatial distributions of the different freshwater components. In the surface layer and as a depth average, all freshwater tracer concentrations are of comparable magnitude, though on a depth average, sea ice and ice shelf are largest. The total freshwater tracer distribution is similar to that of the ice‐shelf tracer field. This implies a potential for ice‐shelf meltwater feedbacks, whereby abundant ice‐shelf meltwater alters the ocean circulation and stratification, affecting melting. Ice‐shelf and sea‐ice freshwater fluxes have the largest interannual variability. The effect of including grounded icebergs and iceberg freshwater flux are studied in detail. The presence of icebergs increases CDW intrusions that reach the base of ice shelves. This suggests another possible feedback mechanism, whereby more icebergs induce greater ice‐shelf melting and hence more icebergs. However, the strength of this potential feedback is dependent on poorly constrained sea‐ice model parameters. These results imply that poorly constrained parameters relating to the ocean freshwater balance, such as those relating to icebergs and sea ice, impact predictions for melting of the West Antarctic Ice Sheet. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Iceberg* Sea ice Northumbria University, Newcastle: Northumbria Research Link (NRL) Amundsen Sea Antarctic West Antarctic Ice Sheet Journal of Geophysical Research: Oceans 125 9 |
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 F900 Others in Physical Sciences |
spellingShingle |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences F900 Others in Physical Sciences Bett, David T. Holland, Paul R. Naveira Garabato, Alberto C. Jenkins, Adrian Dutrieux, Pierre Kimura, Satoshi Fleming, Andrew The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
topic_facet |
F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences F900 Others in Physical Sciences |
description |
The Amundsen Sea has the highest thinning rates of ice shelves in Antarctica. This imbalance is caused by changes in ocean melting induced by warm Circumpolar Deep Water (CDW) intrusions. The resulting changing freshwater balance could affect the on‐shelf currents and mixing. However, a clear understanding of the sources and sinks of freshwater in the region is lacking. Here we use a model of the Amundsen Sea, with passive freshwater tracers, to investigate the relative magnitudes and spatial distributions of the different freshwater components. In the surface layer and as a depth average, all freshwater tracer concentrations are of comparable magnitude, though on a depth average, sea ice and ice shelf are largest. The total freshwater tracer distribution is similar to that of the ice‐shelf tracer field. This implies a potential for ice‐shelf meltwater feedbacks, whereby abundant ice‐shelf meltwater alters the ocean circulation and stratification, affecting melting. Ice‐shelf and sea‐ice freshwater fluxes have the largest interannual variability. The effect of including grounded icebergs and iceberg freshwater flux are studied in detail. The presence of icebergs increases CDW intrusions that reach the base of ice shelves. This suggests another possible feedback mechanism, whereby more icebergs induce greater ice‐shelf melting and hence more icebergs. However, the strength of this potential feedback is dependent on poorly constrained sea‐ice model parameters. These results imply that poorly constrained parameters relating to the ocean freshwater balance, such as those relating to icebergs and sea ice, impact predictions for melting of the West Antarctic Ice Sheet. |
format |
Article in Journal/Newspaper |
author |
Bett, David T. Holland, Paul R. Naveira Garabato, Alberto C. Jenkins, Adrian Dutrieux, Pierre Kimura, Satoshi Fleming, Andrew |
author_facet |
Bett, David T. Holland, Paul R. Naveira Garabato, Alberto C. Jenkins, Adrian Dutrieux, Pierre Kimura, Satoshi Fleming, Andrew |
author_sort |
Bett, David T. |
title |
The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
title_short |
The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
title_full |
The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
title_fullStr |
The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
title_full_unstemmed |
The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet |
title_sort |
impact of the amundsen sea freshwater balance on ocean melting of the west antarctic ice sheet |
publisher |
American Geophysical Union |
publishDate |
2020 |
url |
https://nrl.northumbria.ac.uk/id/eprint/45295/ https://doi.org/10.1029/2020jc016305 https://nrl.northumbria.ac.uk/id/eprint/45295/1/2020JC016305.pdf |
geographic |
Amundsen Sea Antarctic West Antarctic Ice Sheet |
geographic_facet |
Amundsen Sea Antarctic West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Iceberg* Sea ice |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Iceberg* Sea ice |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/45295/1/2020JC016305.pdf Bett, David T., Holland, Paul R., Naveira Garabato, Alberto C., Jenkins, Adrian, Dutrieux, Pierre, Kimura, Satoshi and Fleming, Andrew (2020) The Impact of the Amundsen Sea Freshwater Balance on Ocean Melting of the West Antarctic Ice Sheet. Journal of Geophysical Research: Oceans, 125 (9). ISSN 2169-9275 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2020jc016305 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
9 |
_version_ |
1766375234270658560 |