Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing
International audience The global sea ice-ocean model ORCA2-LIM is used to investigate the impact of the thermal and mechanical forcing associated to the Southern Annular Mode (SAM) on the Antarctic sea ice-ocean system. To do so, the model is driven by idealized forcings based on regressions of the...
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ftccsdartic:oai:HAL:hal-00298442v1 2023-05-15T13:58:32+02:00 Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing Lefebvre, W. Goosse, H. Université Catholique de Louvain = Catholic University of Louvain (UCL) 2005-06-27 https://hal.archives-ouvertes.fr/hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442/document https://hal.archives-ouvertes.fr/hal-00298442/file/osd-2-299-2005.pdf en eng HAL CCSD European Geosciences Union hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442/document https://hal.archives-ouvertes.fr/hal-00298442/file/osd-2-299-2005.pdf info:eu-repo/semantics/OpenAccess ISSN: 1812-0806 EISSN: 1812-0822 Ocean Science Discussions https://hal.archives-ouvertes.fr/hal-00298442 Ocean Science Discussions, European Geosciences Union, 2005, 2 (3), pp.299-329 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2005 ftccsdartic 2021-10-03T00:43:25Z International audience The global sea ice-ocean model ORCA2-LIM is used to investigate the impact of the thermal and mechanical forcing associated to the Southern Annular Mode (SAM) on the Antarctic sea ice-ocean system. To do so, the model is driven by idealized forcings based on regressions of the wind stress and the air temperature to SAM. The wind-stress component strongly affects the overall patterns of the ocean circulation with a northward surface drift, a downwelling at about 45° S and an upwelling in the vicinity of the Antarctic continent when SAM is positive. On the other hand, the thermal forcing has a negligible effect on the ocean currents. For sea ice, both the wind-stress (mechanical) and the air temperature (thermal) components have a significant impact. The mechanical part induces a decrease of the sea ice thickness close to the continent and a sharp decrease of the mean sea ice thickness in the Weddell sector. In general, the sea ice area also diminishes, with a maximum decrease in the Weddell Sea. On the contrary, the thermal part tends to increase the ice concentration in all sectors except in the Weddell Sea, where the ice area shrinks. This thermal effect is the strongest in autumn and in winter due to the larger temperature differences associated with SAM during these seasons. The sum of the thermal and mechaninal effects gives a dipole response of sea ice to the SAM, with a decrease of the ice area in the Weddell Sea and around the Antarctic Peninsula and an increase in the Ross and Amundsen Seas during high SAM years. This is in good agreement with the observed response of the ice cover to SAM. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Sea ice Weddell Sea Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Lefebvre, W. Goosse, H. Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience The global sea ice-ocean model ORCA2-LIM is used to investigate the impact of the thermal and mechanical forcing associated to the Southern Annular Mode (SAM) on the Antarctic sea ice-ocean system. To do so, the model is driven by idealized forcings based on regressions of the wind stress and the air temperature to SAM. The wind-stress component strongly affects the overall patterns of the ocean circulation with a northward surface drift, a downwelling at about 45° S and an upwelling in the vicinity of the Antarctic continent when SAM is positive. On the other hand, the thermal forcing has a negligible effect on the ocean currents. For sea ice, both the wind-stress (mechanical) and the air temperature (thermal) components have a significant impact. The mechanical part induces a decrease of the sea ice thickness close to the continent and a sharp decrease of the mean sea ice thickness in the Weddell sector. In general, the sea ice area also diminishes, with a maximum decrease in the Weddell Sea. On the contrary, the thermal part tends to increase the ice concentration in all sectors except in the Weddell Sea, where the ice area shrinks. This thermal effect is the strongest in autumn and in winter due to the larger temperature differences associated with SAM during these seasons. The sum of the thermal and mechaninal effects gives a dipole response of sea ice to the SAM, with a decrease of the ice area in the Weddell Sea and around the Antarctic Peninsula and an increase in the Ross and Amundsen Seas during high SAM years. This is in good agreement with the observed response of the ice cover to SAM. |
author2 |
Université Catholique de Louvain = Catholic University of Louvain (UCL) |
format |
Article in Journal/Newspaper |
author |
Lefebvre, W. Goosse, H. |
author_facet |
Lefebvre, W. Goosse, H. |
author_sort |
Lefebvre, W. |
title |
Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
title_short |
Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
title_full |
Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
title_fullStr |
Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
title_full_unstemmed |
Influence of the Southern Annular Mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
title_sort |
influence of the southern annular mode on the sea ice-ocean system: the role of the thermal and mechanical forcing |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.archives-ouvertes.fr/hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442/document https://hal.archives-ouvertes.fr/hal-00298442/file/osd-2-299-2005.pdf |
geographic |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell |
genre |
Antarc* Antarctic Antarctic Peninsula Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Sea ice Weddell Sea |
op_source |
ISSN: 1812-0806 EISSN: 1812-0822 Ocean Science Discussions https://hal.archives-ouvertes.fr/hal-00298442 Ocean Science Discussions, European Geosciences Union, 2005, 2 (3), pp.299-329 |
op_relation |
hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442 https://hal.archives-ouvertes.fr/hal-00298442/document https://hal.archives-ouvertes.fr/hal-00298442/file/osd-2-299-2005.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766266879288016896 |