Northward Penetration of Antarctic Intermediate Water off Northwest Africa
24 pages, 20 figures, 1 tables 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 t...
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ftcsic:oai:digital.csic.es:10261/15364 2024-02-11T09:58:19+01:00 Northward Penetration of Antarctic Intermediate Water off Northwest Africa Machín, Francisco Pelegrí, Josep Lluís 2009-03 530832 bytes application/pdf http://hdl.handle.net/10261/15364 https://doi.org/10.1175/2008JPO3825.1 en eng American Meteorological Society https://doi.org/10.1175/2008JPO3825.1 Journal of Physical Oceanography 39(3): 512-535 (2009) 0022-3670 http://hdl.handle.net/10261/15364 doi:10.1175/2008JPO3825.1 open artículo http://purl.org/coar/resource_type/c_6501 2009 ftcsic https://doi.org/10.1175/2008JPO3825.1 2024-01-16T09:23:01Z 24 pages, 20 figures, 1 tables 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 ≡ 10^6 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 The first author has been funded by the Ministerio de Educación y Ciencia through the Juan de la Cierva Program. Funding for this work comes from the Ministerio de Educación y Ciencia, Spain, through Project CANOA (CTM2005–00444/MAR) Peer reviewed Article in Journal/Newspaper Antarc* Antarctic North Atlantic Digital.CSIC (Spanish National Research Council) Antarctic Cierva ENVELOPE(-60.873,-60.873,-64.156,-64.156) Journal of Physical Oceanography 39 3 512 535 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
description |
24 pages, 20 figures, 1 tables 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 ≡ 10^6 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 The first author has been funded by the Ministerio de Educación y Ciencia through the Juan de la Cierva Program. Funding for this work comes from the Ministerio de Educación y Ciencia, Spain, through Project CANOA (CTM2005–00444/MAR) Peer reviewed |
format |
Article in Journal/Newspaper |
author |
Machín, Francisco Pelegrí, Josep Lluís |
spellingShingle |
Machín, Francisco Pelegrí, Josep Lluís Northward Penetration of Antarctic Intermediate Water off Northwest Africa |
author_facet |
Machín, Francisco Pelegrí, Josep Lluís |
author_sort |
Machín, Francisco |
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 |
American Meteorological Society |
publishDate |
2009 |
url |
http://hdl.handle.net/10261/15364 https://doi.org/10.1175/2008JPO3825.1 |
long_lat |
ENVELOPE(-60.873,-60.873,-64.156,-64.156) |
geographic |
Antarctic Cierva |
geographic_facet |
Antarctic Cierva |
genre |
Antarc* Antarctic North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic |
op_relation |
https://doi.org/10.1175/2008JPO3825.1 Journal of Physical Oceanography 39(3): 512-535 (2009) 0022-3670 http://hdl.handle.net/10261/15364 doi:10.1175/2008JPO3825.1 |
op_rights |
open |
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_ |
1790593943310696448 |