Northward penetration of Antarctic intermediate water off Northwest Africa
In this article, historical and climatological datasets are used to investigate the seasonal northward propagation of Antarctic Intermediate Waters (AAIW) along the eastern margin of the North Atlantic subtropical gyre. A cluster analysis for data north of 26°N shows the presence of a substantial nu...
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0022-3670
2009
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Online Access: | http://hdl.handle.net/10553/49050 https://doi.org/10.1175/2008JPO3825.1 |
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ftunivlaspalmas:oai:https://accedacris.ulpgc.es:10553/49050 2023-05-15T13:45:50+02:00 Northward penetration of Antarctic intermediate water off Northwest Africa Machín, F. Pelegrí Llopart,José Luis Machin, Francisco Pelegri, Josep 6602804374 7003869003 1451397 358123 2009 http://hdl.handle.net/10553/49050 https://doi.org/10.1175/2008JPO3825.1 eng eng 0022-3670 Journal of Physical Oceanography 0022-3670 http://hdl.handle.net/10553/49050 doi:10.1175/2008JPO3825.1 67649992243 000265104200003 535 512 39 A-9287-2009 L-5815-2014 Journal of Physical Oceanography [ISSN 0022-3670], v. 39, p. 512-535 251007 Oceanografía física Ocean circulation Intermediate water Density currents Atlantic Ocean Africa 2009 ftunivlaspalmas https://doi.org/10.1175/2008JPO3825.1 2020-02-12T00:09:52Z In this article, historical and climatological datasets are used to investigate the seasonal northward propagation of Antarctic Intermediate Waters (AAIW) along the eastern margin of the North Atlantic subtropical gyre. A cluster analysis for data north of 26°N shows the presence of a substantial number of hydrographic stations with AAIW characteristics that stretch northeast along the African slope. This water mass extends north during fall, as shown both through the comparison of actual and climatological data, and by applying a mixing analysis to normal-to-shore seasonal sections at both 28.5° and 32°N. The mixing analysis is further used with several fall cruises between 32° and 36°N, and shows that at these latitudes the core of AAIW propagates along the 27.5 isoneutral with contributions that reach as much as 50% at 32.5°N. An idealized Sverdrup-type model is used in combination with climatological hydrographic and wind data to examine what forces this eastern boundary propagation. It is found that column stretching, initiated in the tropical North Atlantic, is the dominant term in the vorticity balance of the AAIW stratum, capable of sustaining a winter–spring–summer northward transport of about 3–4 Sv (1 Sv ≡ 106 m3 s−1) that reaches as far north as the Canary Archipelago (28°N). In fall, this transport may continue beyond 28°N, sustained by a near-slope meridional stretching of this water stratum. AAIW probably fades away in the northeastern region as the result of several processes, specially enhanced double diffusion with surrounding waters and interaction with Mediterranean water lenses. Other/Unknown Material Antarc* Antarctic North Atlantic Universidad de Las Palmas de Gran Canaria: Acceda Antarctic Journal of Physical Oceanography 39 3 512 535 |
institution |
Open Polar |
collection |
Universidad de Las Palmas de Gran Canaria: Acceda |
op_collection_id |
ftunivlaspalmas |
language |
English |
topic |
251007 Oceanografía física Ocean circulation Intermediate water Density currents Atlantic Ocean Africa |
spellingShingle |
251007 Oceanografía física Ocean circulation Intermediate water Density currents Atlantic Ocean Africa Machín, F. Pelegrí Llopart,José Luis Northward penetration of Antarctic intermediate water off Northwest Africa |
topic_facet |
251007 Oceanografía física Ocean circulation Intermediate water Density currents Atlantic Ocean Africa |
description |
In this article, historical and climatological datasets are used to investigate the seasonal northward propagation of Antarctic Intermediate Waters (AAIW) along the eastern margin of the North Atlantic subtropical gyre. A cluster analysis for data north of 26°N shows the presence of a substantial number of hydrographic stations with AAIW characteristics that stretch northeast along the African slope. This water mass extends north during fall, as shown both through the comparison of actual and climatological data, and by applying a mixing analysis to normal-to-shore seasonal sections at both 28.5° and 32°N. The mixing analysis is further used with several fall cruises between 32° and 36°N, and shows that at these latitudes the core of AAIW propagates along the 27.5 isoneutral with contributions that reach as much as 50% at 32.5°N. An idealized Sverdrup-type model is used in combination with climatological hydrographic and wind data to examine what forces this eastern boundary propagation. It is found that column stretching, initiated in the tropical North Atlantic, is the dominant term in the vorticity balance of the AAIW stratum, capable of sustaining a winter–spring–summer northward transport of about 3–4 Sv (1 Sv ≡ 106 m3 s−1) that reaches as far north as the Canary Archipelago (28°N). In fall, this transport may continue beyond 28°N, sustained by a near-slope meridional stretching of this water stratum. AAIW probably fades away in the northeastern region as the result of several processes, specially enhanced double diffusion with surrounding waters and interaction with Mediterranean water lenses. |
author2 |
Machin, Francisco Pelegri, Josep 6602804374 7003869003 1451397 358123 |
author |
Machín, F. Pelegrí Llopart,José Luis |
author_facet |
Machín, F. Pelegrí Llopart,José Luis |
author_sort |
Machín, F. |
title |
Northward penetration of Antarctic intermediate water off Northwest Africa |
title_short |
Northward penetration of Antarctic intermediate water off Northwest Africa |
title_full |
Northward penetration of Antarctic intermediate water off Northwest Africa |
title_fullStr |
Northward penetration of Antarctic intermediate water off Northwest Africa |
title_full_unstemmed |
Northward penetration of Antarctic intermediate water off Northwest Africa |
title_sort |
northward penetration of antarctic intermediate water off northwest africa |
publisher |
0022-3670 |
publishDate |
2009 |
url |
http://hdl.handle.net/10553/49050 https://doi.org/10.1175/2008JPO3825.1 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic |
op_source |
Journal of Physical Oceanography [ISSN 0022-3670], v. 39, p. 512-535 |
op_relation |
Journal of Physical Oceanography 0022-3670 http://hdl.handle.net/10553/49050 doi:10.1175/2008JPO3825.1 67649992243 000265104200003 535 512 39 A-9287-2009 L-5815-2014 |
op_doi |
https://doi.org/10.1175/2008JPO3825.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
39 |
container_issue |
3 |
container_start_page |
512 |
op_container_end_page |
535 |
_version_ |
1766231500735381504 |