Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model
Some ocean modeling studies have identified a potential tipping point from a low to a high basal melt regime beneath the Filchner–Ronne Ice Shelf (FRIS), Antarctica, with significant implications for subsequent Antarctic ice sheet mass loss. To date, investigation of the climate drivers and impacts...
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Copernicus Publications
2024
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Online Access: | https://doi.org/10.5194/tc-18-2917-2024 https://doaj.org/article/b59c770c473d44d7a2b3e45eb2e5e80b |
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ftdoajarticles:oai:doaj.org/article:b59c770c473d44d7a2b3e45eb2e5e80b 2024-09-15T17:42:18+00:00 Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model M. J. Hoffman C. Branecky Begeman X. S. Asay-Davis D. Comeau A. Barthel S. F. Price J. D. Wolfe 2024-06-01T00:00:00Z https://doi.org/10.5194/tc-18-2917-2024 https://doaj.org/article/b59c770c473d44d7a2b3e45eb2e5e80b EN eng Copernicus Publications https://tc.copernicus.org/articles/18/2917/2024/tc-18-2917-2024.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-18-2917-2024 1994-0416 1994-0424 https://doaj.org/article/b59c770c473d44d7a2b3e45eb2e5e80b The Cryosphere, Vol 18, Pp 2917-2937 (2024) Environmental sciences GE1-350 Geology QE1-996.5 article 2024 ftdoajarticles https://doi.org/10.5194/tc-18-2917-2024 2024-08-05T17:49:07Z Some ocean modeling studies have identified a potential tipping point from a low to a high basal melt regime beneath the Filchner–Ronne Ice Shelf (FRIS), Antarctica, with significant implications for subsequent Antarctic ice sheet mass loss. To date, investigation of the climate drivers and impacts of this possible event have been limited because ice-shelf cavities and ice-shelf melting are only now starting to be included in global climate models. Using a global ocean–sea-ice configuration of the Energy Exascale Earth System Model (E3SM) that represents both ocean circulations and melting within ice-shelf cavities, we explore freshwater triggers (iceberg melt and ice-shelf basal melt) of a transition to a high-melt regime at FRIS in a low-resolution (30 km in the Southern Ocean) global ocean–sea-ice model. We find that a realistic spatial distribution of iceberg melt fluxes is necessary to prevent the FRIS melt regime change from unrealistically occurring under historical-reanalysis-based atmospheric forcing. Further, improvement of the default parameterization for mesoscale eddy mixing significantly reduces a large regional fresh bias and weak Antarctic Slope Front structure, both of which precondition the model to melt regime change. Using two different stable model configurations, we explore the sensitivity of FRIS melt regime change to regional ice-sheet freshwater fluxes. Through a series of sensitivity experiments prescribing incrementally increasing melt rates from the smaller, neighboring ice shelves in the eastern Weddell Sea, we demonstrate the potential for an ice-shelf melt “domino effect” should the upstream ice shelves experience increased melt rates. The experiments also reveal that modest ice-shelf melt biases in a model, especially at coarse ocean resolution where narrow continental shelf dynamics are not well resolved, can lead to an unrealistic melt regime change at downstream ice shelves. Thus, we find that remote connections between melt fluxes at different ice shelves are sensitive to ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice Southern Ocean The Cryosphere Weddell Sea Directory of Open Access Journals: DOAJ Articles The Cryosphere 18 6 2917 2937 |
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English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
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Environmental sciences GE1-350 Geology QE1-996.5 M. J. Hoffman C. Branecky Begeman X. S. Asay-Davis D. Comeau A. Barthel S. F. Price J. D. Wolfe Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Some ocean modeling studies have identified a potential tipping point from a low to a high basal melt regime beneath the Filchner–Ronne Ice Shelf (FRIS), Antarctica, with significant implications for subsequent Antarctic ice sheet mass loss. To date, investigation of the climate drivers and impacts of this possible event have been limited because ice-shelf cavities and ice-shelf melting are only now starting to be included in global climate models. Using a global ocean–sea-ice configuration of the Energy Exascale Earth System Model (E3SM) that represents both ocean circulations and melting within ice-shelf cavities, we explore freshwater triggers (iceberg melt and ice-shelf basal melt) of a transition to a high-melt regime at FRIS in a low-resolution (30 km in the Southern Ocean) global ocean–sea-ice model. We find that a realistic spatial distribution of iceberg melt fluxes is necessary to prevent the FRIS melt regime change from unrealistically occurring under historical-reanalysis-based atmospheric forcing. Further, improvement of the default parameterization for mesoscale eddy mixing significantly reduces a large regional fresh bias and weak Antarctic Slope Front structure, both of which precondition the model to melt regime change. Using two different stable model configurations, we explore the sensitivity of FRIS melt regime change to regional ice-sheet freshwater fluxes. Through a series of sensitivity experiments prescribing incrementally increasing melt rates from the smaller, neighboring ice shelves in the eastern Weddell Sea, we demonstrate the potential for an ice-shelf melt “domino effect” should the upstream ice shelves experience increased melt rates. The experiments also reveal that modest ice-shelf melt biases in a model, especially at coarse ocean resolution where narrow continental shelf dynamics are not well resolved, can lead to an unrealistic melt regime change at downstream ice shelves. Thus, we find that remote connections between melt fluxes at different ice shelves are sensitive to ... |
format |
Article in Journal/Newspaper |
author |
M. J. Hoffman C. Branecky Begeman X. S. Asay-Davis D. Comeau A. Barthel S. F. Price J. D. Wolfe |
author_facet |
M. J. Hoffman C. Branecky Begeman X. S. Asay-Davis D. Comeau A. Barthel S. F. Price J. D. Wolfe |
author_sort |
M. J. Hoffman |
title |
Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
title_short |
Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
title_full |
Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
title_fullStr |
Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
title_full_unstemmed |
Ice-shelf freshwater triggers for the Filchner–Ronne Ice Shelf melt tipping point in a global ocean–sea-ice model |
title_sort |
ice-shelf freshwater triggers for the filchner–ronne ice shelf melt tipping point in a global ocean–sea-ice model |
publisher |
Copernicus Publications |
publishDate |
2024 |
url |
https://doi.org/10.5194/tc-18-2917-2024 https://doaj.org/article/b59c770c473d44d7a2b3e45eb2e5e80b |
genre |
Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice Southern Ocean The Cryosphere Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice Southern Ocean The Cryosphere Weddell Sea |
op_source |
The Cryosphere, Vol 18, Pp 2917-2937 (2024) |
op_relation |
https://tc.copernicus.org/articles/18/2917/2024/tc-18-2917-2024.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-18-2917-2024 1994-0416 1994-0424 https://doaj.org/article/b59c770c473d44d7a2b3e45eb2e5e80b |
op_doi |
https://doi.org/10.5194/tc-18-2917-2024 |
container_title |
The Cryosphere |
container_volume |
18 |
container_issue |
6 |
container_start_page |
2917 |
op_container_end_page |
2937 |
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1810488817231069184 |