Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior.
International audience Data from a hydrographic section carried out in January-March 1994 offshore from the eastern coast of South America from 50S to 10N, are used to quantify the full-depth exchanges of water between the western boundary currents and the ocean interior. In the upper and intermedia...
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ftunivnantes:oai:HAL:hal-00274717v1 2023-05-15T14:00:44+02:00 Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. Arhan, Michel Mercier, H. Wienders, N. 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) 2000-11 https://hal.science/hal-00274717 https://doi.org/10.1357/002224000763485782 en eng HAL CCSD Yale University info:eu-repo/semantics/altIdentifier/doi/10.1357/002224000763485782 hal-00274717 https://hal.science/hal-00274717 doi:10.1357/002224000763485782 ISSN: 0022-2402 EISSN: 1543-9542 Journal of marine research https://hal.science/hal-00274717 Journal of marine research, 2000, 58 (6), pp.1007-1039. ⟨10.1357/002224000763485782⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2000 ftunivnantes https://doi.org/10.1357/002224000763485782 2023-02-08T06:07:02Z International audience Data from a hydrographic section carried out in January-March 1994 offshore from the eastern coast of South America from 50S to 10N, are used to quantify the full-depth exchanges of water between the western boundary currents and the ocean interior. In the upper and intermediate layers, the westward transport associated with the southern branch of the South Equatorial Current was 49 Sv at the time of the cruise. The transports of the central and northern branches in the upper 200 m were 17 Sv and 12 Sv, respectively. After subtraction of the parts that recirculate in the subtropical, subequatorial, and equatorial domains, the fraction of the South Equatorial Current that effectively contributes to the warm water export to the North Atlantic is estimated at 18 Sv. The poleward boundary of the current southern branch is at 31S through the whole thickness of the subtropical gyre, but the latitude of the northern boundary varies from 7°30primeS at the surface to 27S at 1400 m depth. The estimated latitude of its bifurcation into the Brazil Current and North Brazil Undercurrent also varies downward from about 14S at the surface to 28S at a depth of 600 m. In the North Atlantic Deep Water, eastward flows exceeding 10 Sv are observed at 3°-4° of latitude in both hemispheres, at 10S, and at 34S-30S. Between 4S and 17S, a net westward flow with an estimated transport of 19 Sv reinforces the southward deep western boundary current. Cyclonic circulations of Antarctic Bottom Water along the western boundaries of the Argentine and Brazil basins have amplitudes of 15 Sv and 13 Sv, respectively, exceeding those of the interbasin exchanges. The net alongshore transport of this water mass between the hydrographic section and the continental slope reverses to a southward direction from 13S to 27S, probably in relation with an eastward shift of the equatorward near-bottom boundary current at these latitudes. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Université de Nantes: HAL-UNIV-NANTES Antarctic Argentine Journal of Marine Research 58 6 1007 1039 |
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 Arhan, Michel Mercier, H. Wienders, N. Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Data from a hydrographic section carried out in January-March 1994 offshore from the eastern coast of South America from 50S to 10N, are used to quantify the full-depth exchanges of water between the western boundary currents and the ocean interior. In the upper and intermediate layers, the westward transport associated with the southern branch of the South Equatorial Current was 49 Sv at the time of the cruise. The transports of the central and northern branches in the upper 200 m were 17 Sv and 12 Sv, respectively. After subtraction of the parts that recirculate in the subtropical, subequatorial, and equatorial domains, the fraction of the South Equatorial Current that effectively contributes to the warm water export to the North Atlantic is estimated at 18 Sv. The poleward boundary of the current southern branch is at 31S through the whole thickness of the subtropical gyre, but the latitude of the northern boundary varies from 7°30primeS at the surface to 27S at 1400 m depth. The estimated latitude of its bifurcation into the Brazil Current and North Brazil Undercurrent also varies downward from about 14S at the surface to 28S at a depth of 600 m. In the North Atlantic Deep Water, eastward flows exceeding 10 Sv are observed at 3°-4° of latitude in both hemispheres, at 10S, and at 34S-30S. Between 4S and 17S, a net westward flow with an estimated transport of 19 Sv reinforces the southward deep western boundary current. Cyclonic circulations of Antarctic Bottom Water along the western boundaries of the Argentine and Brazil basins have amplitudes of 15 Sv and 13 Sv, respectively, exceeding those of the interbasin exchanges. The net alongshore transport of this water mass between the hydrographic section and the continental slope reverses to a southward direction from 13S to 27S, probably in relation with an eastward shift of the equatorward near-bottom boundary current at these latitudes. |
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 |
Arhan, Michel Mercier, H. Wienders, N. |
author_facet |
Arhan, Michel Mercier, H. Wienders, N. |
author_sort |
Arhan, Michel |
title |
Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
title_short |
Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
title_full |
Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
title_fullStr |
Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
title_full_unstemmed |
Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. |
title_sort |
circulation at the western boundary of the south and equatorial atlantic: exchanges with the ocean interior. |
publisher |
HAL CCSD |
publishDate |
2000 |
url |
https://hal.science/hal-00274717 https://doi.org/10.1357/002224000763485782 |
geographic |
Antarctic Argentine |
geographic_facet |
Antarctic Argentine |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
op_source |
ISSN: 0022-2402 EISSN: 1543-9542 Journal of marine research https://hal.science/hal-00274717 Journal of marine research, 2000, 58 (6), pp.1007-1039. ⟨10.1357/002224000763485782⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1357/002224000763485782 hal-00274717 https://hal.science/hal-00274717 doi:10.1357/002224000763485782 |
op_doi |
https://doi.org/10.1357/002224000763485782 |
container_title |
Journal of Marine Research |
container_volume |
58 |
container_issue |
6 |
container_start_page |
1007 |
op_container_end_page |
1039 |
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1766270078735613952 |