Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6
Ice-shelf–ocean interactions are a major source of freshwater on the Antarctic continental shelf and have a strong impact on ocean properties, ocean circulation and sea ice. However, climate models based on the ocean–sea ice model NEMO (Nucleus for European Modelling of the Ocean) currently do not i...
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ftdoajarticles:oai:doaj.org/article:242f81b967554888b9bb0ef7802c3bdb 2023-05-15T13:47:39+02:00 Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 P. Mathiot A. Jenkins C. Harris G. Madec 2017-07-01T00:00:00Z https://doi.org/10.5194/gmd-10-2849-2017 https://doaj.org/article/242f81b967554888b9bb0ef7802c3bdb EN eng Copernicus Publications https://www.geosci-model-dev.net/10/2849/2017/gmd-10-2849-2017.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-10-2849-2017 1991-959X 1991-9603 https://doaj.org/article/242f81b967554888b9bb0ef7802c3bdb Geoscientific Model Development, Vol 10, Pp 2849-2874 (2017) Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/gmd-10-2849-2017 2022-12-30T22:00:09Z Ice-shelf–ocean interactions are a major source of freshwater on the Antarctic continental shelf and have a strong impact on ocean properties, ocean circulation and sea ice. However, climate models based on the ocean–sea ice model NEMO (Nucleus for European Modelling of the Ocean) currently do not include these interactions in any detail. The capability of explicitly simulating the circulation beneath ice shelves is introduced in the non-linear free surface model NEMO. Its implementation into the NEMO framework and its assessment in an idealised and realistic circum-Antarctic configuration is described in this study. Compared with the current prescription of ice shelf melting (i.e. at the surface), inclusion of open sub-ice-shelf cavities leads to a decrease in sea ice thickness along the coast, a weakening of the ocean stratification on the shelf, a decrease in salinity of high-salinity shelf water on the Ross and Weddell sea shelves and an increase in the strength of the gyres that circulate within the over-deepened basins on the West Antarctic continental shelf. Mimicking the overturning circulation under the ice shelves by introducing a prescribed meltwater flux over the depth range of the ice shelf base, rather than at the surface, is also assessed. It yields similar improvements in the simulated ocean properties and circulation over the Antarctic continental shelf to those from the explicit ice shelf cavity representation. With the ice shelf cavities opened, the widely used <q>three equation</q> ice shelf melting formulation, which enables an interactive computation of melting, is tested. Comparison with observational estimates of ice shelf melting indicates realistic results for most ice shelves. However, melting rates for the Amery, Getz and George VI ice shelves are considerably overestimated. Article in Journal/Newspaper Antarc* Antarctic Ice Shelf Ice Shelves Sea ice Weddell Sea Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Weddell Sea Weddell Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) Geoscientific Model Development 10 7 2849 2874 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 P. Mathiot A. Jenkins C. Harris G. Madec Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
topic_facet |
Geology QE1-996.5 |
description |
Ice-shelf–ocean interactions are a major source of freshwater on the Antarctic continental shelf and have a strong impact on ocean properties, ocean circulation and sea ice. However, climate models based on the ocean–sea ice model NEMO (Nucleus for European Modelling of the Ocean) currently do not include these interactions in any detail. The capability of explicitly simulating the circulation beneath ice shelves is introduced in the non-linear free surface model NEMO. Its implementation into the NEMO framework and its assessment in an idealised and realistic circum-Antarctic configuration is described in this study. Compared with the current prescription of ice shelf melting (i.e. at the surface), inclusion of open sub-ice-shelf cavities leads to a decrease in sea ice thickness along the coast, a weakening of the ocean stratification on the shelf, a decrease in salinity of high-salinity shelf water on the Ross and Weddell sea shelves and an increase in the strength of the gyres that circulate within the over-deepened basins on the West Antarctic continental shelf. Mimicking the overturning circulation under the ice shelves by introducing a prescribed meltwater flux over the depth range of the ice shelf base, rather than at the surface, is also assessed. It yields similar improvements in the simulated ocean properties and circulation over the Antarctic continental shelf to those from the explicit ice shelf cavity representation. With the ice shelf cavities opened, the widely used <q>three equation</q> ice shelf melting formulation, which enables an interactive computation of melting, is tested. Comparison with observational estimates of ice shelf melting indicates realistic results for most ice shelves. However, melting rates for the Amery, Getz and George VI ice shelves are considerably overestimated. |
format |
Article in Journal/Newspaper |
author |
P. Mathiot A. Jenkins C. Harris G. Madec |
author_facet |
P. Mathiot A. Jenkins C. Harris G. Madec |
author_sort |
P. Mathiot |
title |
Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
title_short |
Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
title_full |
Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
title_fullStr |
Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
title_full_unstemmed |
Explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model NEMO 3.6 |
title_sort |
explicit representation and parametrised impacts of under ice shelf seas in the z ∗ coordinate ocean model nemo 3.6 |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/gmd-10-2849-2017 https://doaj.org/article/242f81b967554888b9bb0ef7802c3bdb |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(-145.217,-145.217,-76.550,-76.550) |
geographic |
Antarctic The Antarctic Weddell Sea Weddell Amery Getz |
geographic_facet |
Antarctic The Antarctic Weddell Sea Weddell Amery Getz |
genre |
Antarc* Antarctic Ice Shelf Ice Shelves Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctic Ice Shelf Ice Shelves Sea ice Weddell Sea |
op_source |
Geoscientific Model Development, Vol 10, Pp 2849-2874 (2017) |
op_relation |
https://www.geosci-model-dev.net/10/2849/2017/gmd-10-2849-2017.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-10-2849-2017 1991-959X 1991-9603 https://doaj.org/article/242f81b967554888b9bb0ef7802c3bdb |
op_doi |
https://doi.org/10.5194/gmd-10-2849-2017 |
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Geoscientific Model Development |
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10 |
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7 |
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2849 |
op_container_end_page |
2874 |
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