Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica
Coastal polynyas of the Southern Ocean play a central role in the ventilation of the deep ocean and affect the stability of ice shelves. It appears crucial to incorporate them into climate models, but it is unclear how to adequately simulate them. In particular, there is no consensus on the atmosphe...
Published in: | Ocean Modelling |
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Online Access: | http://hdl.handle.net/2078.1/254481 https://doi.org/10.1016/j.ocemod.2021.101901 |
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ftunistlouisbrus:oai:dial.uclouvain.be:boreal:254481 2024-05-12T07:53:15+00:00 Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica Huot, Pierre Kittel, Christoph Fichefet, Thierry Jourdain, Nicolas C. Sterlin, Jean Fettweis, Xavier UCL - SST/ELI/ELIC - Earth & Climate 2021 http://hdl.handle.net/2078.1/254481 https://doi.org/10.1016/j.ocemod.2021.101901 eng eng Elsevier Inc. boreal:254481 http://hdl.handle.net/2078.1/254481 doi:10.1016/j.ocemod.2021.101901 urn:ISSN:1463-5003 urn:EISSN:1463-5011 info:eu-repo/semantics/openAccess Ocean Modelling, Vol. 168, p. 101901 (2021) Atmospheric Science Geotechnical Engineering and Engineering Geology Computer Science (miscellaneous) Oceanography info:eu-repo/semantics/article 2021 ftunistlouisbrus https://doi.org/10.1016/j.ocemod.2021.101901 2024-04-18T17:14:47Z Coastal polynyas of the Southern Ocean play a central role in the ventilation of the deep ocean and affect the stability of ice shelves. It appears crucial to incorporate them into climate models, but it is unclear how to adequately simulate them. In particular, there is no consensus on the atmospheric forcing resolution needed to appropriately model the sea ice in coastal Antarctica. A high resolution might be required to represent the local winds such as katabatic winds which are key drivers of coastal polynyas. To fill in this gap, we have tested the sensitivity of sea ice and air-sea-ice interactions to the resolution of the atmospheric forcing in a high-resolution ocean–sea ice model. A set of regional atmospheric simulations at horizontal resolutions of 20, 10, and 5 km are performed with an atmospheric regional model and used to force three ocean–sea ice simulations in the Adélie Land sector, East Antarctica. Due to the better representation of topography with a refined grid, the offshore component of coastal winds becomes stronger at increased resolution. The wind intensification is particularly strong down valleys channelizing the katabatic flow, with increase in wind speed ranging between 1 and 3 m/s. Under a higher resolution forcing, polynyas open more frequently and are wider. This fosters the growth rate of sea ice in polynyas, while landfast ice and pack ice are weakly affected. In polynyas, the production of sea ice is increased by up to 30% at 5 km resolution compared to 20 km resolution. Polynyas downstream of the katabatic wind pathway are more affected than the ones driven by easterly winds, highlighting the importance of the local wind conditions. Brine rejection associated with these higher sea ice production rates affects the salinity budget of the ocean and enhances both the volume and density of the dense Shelf Water produced off Adélie Land. These results underpin the need to better account for local coastal winds and polynyas in ocean and climate models. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Ice Shelves Sea ice Southern Ocean DIAL@USL-B (Université Saint-Louis, Bruxelles) East Antarctica Southern Ocean Ocean Modelling 168 101901 |
institution |
Open Polar |
collection |
DIAL@USL-B (Université Saint-Louis, Bruxelles) |
op_collection_id |
ftunistlouisbrus |
language |
English |
topic |
Atmospheric Science Geotechnical Engineering and Engineering Geology Computer Science (miscellaneous) Oceanography |
spellingShingle |
Atmospheric Science Geotechnical Engineering and Engineering Geology Computer Science (miscellaneous) Oceanography Huot, Pierre Kittel, Christoph Fichefet, Thierry Jourdain, Nicolas C. Sterlin, Jean Fettweis, Xavier Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
topic_facet |
Atmospheric Science Geotechnical Engineering and Engineering Geology Computer Science (miscellaneous) Oceanography |
description |
Coastal polynyas of the Southern Ocean play a central role in the ventilation of the deep ocean and affect the stability of ice shelves. It appears crucial to incorporate them into climate models, but it is unclear how to adequately simulate them. In particular, there is no consensus on the atmospheric forcing resolution needed to appropriately model the sea ice in coastal Antarctica. A high resolution might be required to represent the local winds such as katabatic winds which are key drivers of coastal polynyas. To fill in this gap, we have tested the sensitivity of sea ice and air-sea-ice interactions to the resolution of the atmospheric forcing in a high-resolution ocean–sea ice model. A set of regional atmospheric simulations at horizontal resolutions of 20, 10, and 5 km are performed with an atmospheric regional model and used to force three ocean–sea ice simulations in the Adélie Land sector, East Antarctica. Due to the better representation of topography with a refined grid, the offshore component of coastal winds becomes stronger at increased resolution. The wind intensification is particularly strong down valleys channelizing the katabatic flow, with increase in wind speed ranging between 1 and 3 m/s. Under a higher resolution forcing, polynyas open more frequently and are wider. This fosters the growth rate of sea ice in polynyas, while landfast ice and pack ice are weakly affected. In polynyas, the production of sea ice is increased by up to 30% at 5 km resolution compared to 20 km resolution. Polynyas downstream of the katabatic wind pathway are more affected than the ones driven by easterly winds, highlighting the importance of the local wind conditions. Brine rejection associated with these higher sea ice production rates affects the salinity budget of the ocean and enhances both the volume and density of the dense Shelf Water produced off Adélie Land. These results underpin the need to better account for local coastal winds and polynyas in ocean and climate models. |
author2 |
UCL - SST/ELI/ELIC - Earth & Climate |
format |
Article in Journal/Newspaper |
author |
Huot, Pierre Kittel, Christoph Fichefet, Thierry Jourdain, Nicolas C. Sterlin, Jean Fettweis, Xavier |
author_facet |
Huot, Pierre Kittel, Christoph Fichefet, Thierry Jourdain, Nicolas C. Sterlin, Jean Fettweis, Xavier |
author_sort |
Huot, Pierre |
title |
Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
title_short |
Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
title_full |
Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
title_fullStr |
Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
title_full_unstemmed |
Effects of the atmospheric forcing resolution on simulated sea ice and polynyas off Adélie Land, East Antarctica |
title_sort |
effects of the atmospheric forcing resolution on simulated sea ice and polynyas off adã©lie land, east antarctica |
publisher |
Elsevier Inc. |
publishDate |
2021 |
url |
http://hdl.handle.net/2078.1/254481 https://doi.org/10.1016/j.ocemod.2021.101901 |
geographic |
East Antarctica Southern Ocean |
geographic_facet |
East Antarctica Southern Ocean |
genre |
Antarc* Antarctica East Antarctica Ice Shelves Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctica East Antarctica Ice Shelves Sea ice Southern Ocean |
op_source |
Ocean Modelling, Vol. 168, p. 101901 (2021) |
op_relation |
boreal:254481 http://hdl.handle.net/2078.1/254481 doi:10.1016/j.ocemod.2021.101901 urn:ISSN:1463-5003 urn:EISSN:1463-5011 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.ocemod.2021.101901 |
container_title |
Ocean Modelling |
container_volume |
168 |
container_start_page |
101901 |
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1798841723321843712 |