Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic.
International audience The seasonal regime associated with the eastern part of the cyclonic tropical gyre in the North Atlantic is studied using a high-resolution model. The model reproduces a vertical water mass transition (between South and North Atlantic Central Water) previously observed near σ0...
Published in: | Deep Sea Research Part I: Oceanographic Research Papers |
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ftunivnantes:oai:HAL:hal-00270743v1 2023-05-15T17:30:43+02:00 Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. Elmoussaoui, A. Arhan, Michel Tréguier, Anne-Marie Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2005-07 https://hal.science/hal-00270743 https://doi.org/10.1016/j.dsr.2005.01.010 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.dsr.2005.01.010 hal-00270743 https://hal.science/hal-00270743 doi:10.1016/j.dsr.2005.01.010 ISSN: 0967-0637 Deep Sea Research Part I: Oceanographic Research Papers https://hal.science/hal-00270743 Deep Sea Research Part I: Oceanographic Research Papers, 2005, 52 (7), pp.1093-1120. ⟨10.1016/j.dsr.2005.01.010⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2005 ftunivnantes https://doi.org/10.1016/j.dsr.2005.01.010 2023-02-08T06:16:51Z International audience The seasonal regime associated with the eastern part of the cyclonic tropical gyre in the North Atlantic is studied using a high-resolution model. The model reproduces a vertical water mass transition (between South and North Atlantic Central Water) previously observed near σ0=26.8, which approximately coincides with the base of the North Equatorial Undercurrent (NEUC). The same density may be taken as the lower limit of the large-scale cyclonic flow. The gyre southern flank is formed of the North Equatorial Countercurrent (NECC) in the near-surface layer, and of the NEUC and deep NECC (when this current is developed) in the Central Water. Its poleward limb is made up from the Ekman drift of the trade winds, a northeastward extension of the NEUC/deep NECC, and reinforced by an extension of the Guinea undercurrent along the African continental slope. Model experiments with two different wind forcings were carried out to estimate the transports across 12°N, an approximate gyre central latitude. The time-averaged transport for densities lower than σ1=32.3 and to the east of 35°W is around 4 Sv northward, about one-third of the basin-wide net value which measures the Meridional Overturning Circulation. The near-surface layer accounts for about 3 Sv, and the Central Water for more than 1 Sv, in keeping with the presence of South Atlantic Central Water in the tropical eastern basin. The eastern basin near-surface flow is lowest in summer, when the trade winds nearly vanish at this latitude. In this season the NECC, though having entered its phase of intensification, leaves the region of positive wind stress curl, and temporarily does not act as the tropical gyre southern limb. At the subsurface, most of the NEUC folds up westward at not, vert, similar10°N in winter, thus forming an inner circulation of the basin-wide gyre, previously reported from observations. The cyclonic flow associated with the Guinea Dome is another inner circulation, which the model found to be permanent below the ... Article in Journal/Newspaper North Atlantic Université de Nantes: HAL-UNIV-NANTES Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Deep Sea Research Part I: Oceanographic Research Papers 52 7 1093 1120 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
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 Elmoussaoui, A. Arhan, Michel Tréguier, Anne-Marie Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience The seasonal regime associated with the eastern part of the cyclonic tropical gyre in the North Atlantic is studied using a high-resolution model. The model reproduces a vertical water mass transition (between South and North Atlantic Central Water) previously observed near σ0=26.8, which approximately coincides with the base of the North Equatorial Undercurrent (NEUC). The same density may be taken as the lower limit of the large-scale cyclonic flow. The gyre southern flank is formed of the North Equatorial Countercurrent (NECC) in the near-surface layer, and of the NEUC and deep NECC (when this current is developed) in the Central Water. Its poleward limb is made up from the Ekman drift of the trade winds, a northeastward extension of the NEUC/deep NECC, and reinforced by an extension of the Guinea undercurrent along the African continental slope. Model experiments with two different wind forcings were carried out to estimate the transports across 12°N, an approximate gyre central latitude. The time-averaged transport for densities lower than σ1=32.3 and to the east of 35°W is around 4 Sv northward, about one-third of the basin-wide net value which measures the Meridional Overturning Circulation. The near-surface layer accounts for about 3 Sv, and the Central Water for more than 1 Sv, in keeping with the presence of South Atlantic Central Water in the tropical eastern basin. The eastern basin near-surface flow is lowest in summer, when the trade winds nearly vanish at this latitude. In this season the NECC, though having entered its phase of intensification, leaves the region of positive wind stress curl, and temporarily does not act as the tropical gyre southern limb. At the subsurface, most of the NEUC folds up westward at not, vert, similar10°N in winter, thus forming an inner circulation of the basin-wide gyre, previously reported from observations. The cyclonic flow associated with the Guinea Dome is another inner circulation, which the model found to be permanent below the ... |
author2 |
Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Elmoussaoui, A. Arhan, Michel Tréguier, Anne-Marie |
author_facet |
Elmoussaoui, A. Arhan, Michel Tréguier, Anne-Marie |
author_sort |
Elmoussaoui, A. |
title |
Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
title_short |
Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
title_full |
Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
title_fullStr |
Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
title_full_unstemmed |
Model-inferred upper ocean circulation in the eastern tropics of the North Atlantic. |
title_sort |
model-inferred upper ocean circulation in the eastern tropics of the north atlantic. |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.science/hal-00270743 https://doi.org/10.1016/j.dsr.2005.01.010 |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Curl |
geographic_facet |
Curl |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0967-0637 Deep Sea Research Part I: Oceanographic Research Papers https://hal.science/hal-00270743 Deep Sea Research Part I: Oceanographic Research Papers, 2005, 52 (7), pp.1093-1120. ⟨10.1016/j.dsr.2005.01.010⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.dsr.2005.01.010 hal-00270743 https://hal.science/hal-00270743 doi:10.1016/j.dsr.2005.01.010 |
op_doi |
https://doi.org/10.1016/j.dsr.2005.01.010 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
52 |
container_issue |
7 |
container_start_page |
1093 |
op_container_end_page |
1120 |
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