Localized Acceleration of the Antarctic Circumpolar Current
The influence of wind forcing on the strength of the Antarctic Circumpolar Current (ACC) is explored using realistic eddying simulations. The ACC transport is found to be set by both the zonal wind stress, at latitudes of Drake Passage, and by the curl of the wind stress, localized in the western So...
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ftccsdartic:oai:HAL:hal-00592072v1 2023-05-15T14:00:54+02:00 Localized Acceleration of the Antarctic Circumpolar Current Zika, Jan D. Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF) 2011-05-11 https://hal.archives-ouvertes.fr/hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072/document https://hal.archives-ouvertes.fr/hal-00592072/file/ACCaccelerator_Zikaetal_asSubmitted_y11m05d11.pdf en eng HAL CCSD hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072/document https://hal.archives-ouvertes.fr/hal-00592072/file/ACCaccelerator_Zikaetal_asSubmitted_y11m05d11.pdf info:eu-repo/semantics/OpenAccess https://hal.archives-ouvertes.fr/hal-00592072 2011 [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/preprint Preprints, Working Papers, . 2011 ftccsdartic 2021-10-24T17:49:32Z The influence of wind forcing on the strength of the Antarctic Circumpolar Current (ACC) is explored using realistic eddying simulations. The ACC transport is found to be set by both the zonal wind stress, at latitudes of Drake Passage, and by the curl of the wind stress, localized in the western South Atlantic. As such, for certain wind stress patterns, the ACC transport is dramatically increased, without any increase in the mean zonal wind stress. The mechanism by which local wind curl variations effect the strength of the ACC is as follows: In the western South Atlantic the ACC meanders over the shallowest topo- graphic features of its circumpolar path. In this region a positive wind curl induces vortex compression. This compression helps the ACC to move equator-ward and over the shallow topography. This interaction reduces the momentum transfer to the bottom for a given ACC transport. The total ACC transport then increases so that the momentum imparted at the sea surface is transferred to the sea floor. Local wind curl variations in the western South Atlantic are found to be far more effective at driving year to year fluctuations in ACC transport than the zonal wind stress. In addition, changes both in the pattern and in the magnitude of the Southern Hemisphere westerlies, concurrent with observed climate change, are likely to have both had an accelerating influence on the ACC of equivalent magnitude. Report Antarc* Antarctic Drake Passage Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic The Antarctic Drake Passage Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
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.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Zika, Jan D. Localized Acceleration of the Antarctic Circumpolar Current |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
The influence of wind forcing on the strength of the Antarctic Circumpolar Current (ACC) is explored using realistic eddying simulations. The ACC transport is found to be set by both the zonal wind stress, at latitudes of Drake Passage, and by the curl of the wind stress, localized in the western South Atlantic. As such, for certain wind stress patterns, the ACC transport is dramatically increased, without any increase in the mean zonal wind stress. The mechanism by which local wind curl variations effect the strength of the ACC is as follows: In the western South Atlantic the ACC meanders over the shallowest topo- graphic features of its circumpolar path. In this region a positive wind curl induces vortex compression. This compression helps the ACC to move equator-ward and over the shallow topography. This interaction reduces the momentum transfer to the bottom for a given ACC transport. The total ACC transport then increases so that the momentum imparted at the sea surface is transferred to the sea floor. Local wind curl variations in the western South Atlantic are found to be far more effective at driving year to year fluctuations in ACC transport than the zonal wind stress. In addition, changes both in the pattern and in the magnitude of the Southern Hemisphere westerlies, concurrent with observed climate change, are likely to have both had an accelerating influence on the ACC of equivalent magnitude. |
author2 |
Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF) |
format |
Report |
author |
Zika, Jan D. |
author_facet |
Zika, Jan D. |
author_sort |
Zika, Jan D. |
title |
Localized Acceleration of the Antarctic Circumpolar Current |
title_short |
Localized Acceleration of the Antarctic Circumpolar Current |
title_full |
Localized Acceleration of the Antarctic Circumpolar Current |
title_fullStr |
Localized Acceleration of the Antarctic Circumpolar Current |
title_full_unstemmed |
Localized Acceleration of the Antarctic Circumpolar Current |
title_sort |
localized acceleration of the antarctic circumpolar current |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://hal.archives-ouvertes.fr/hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072/document https://hal.archives-ouvertes.fr/hal-00592072/file/ACCaccelerator_Zikaetal_asSubmitted_y11m05d11.pdf |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Antarctic The Antarctic Drake Passage Curl |
geographic_facet |
Antarctic The Antarctic Drake Passage Curl |
genre |
Antarc* Antarctic Drake Passage |
genre_facet |
Antarc* Antarctic Drake Passage |
op_source |
https://hal.archives-ouvertes.fr/hal-00592072 2011 |
op_relation |
hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072 https://hal.archives-ouvertes.fr/hal-00592072/document https://hal.archives-ouvertes.fr/hal-00592072/file/ACCaccelerator_Zikaetal_asSubmitted_y11m05d11.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766270291018776576 |