Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995.
International audience The upper-layer circulation in the eastern basin of the South Atlantic was studied from hydrographic and direct velocity measurements along WOCE lines A11, A13 and A14. A13 and A14 provide quasi-meridional samplings of the equatorial, subequatorial and subtropical circulation...
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ftunivnantes:oai:HAL:hal-00271267v1 2023-05-15T18:21:17+02:00 Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. Mercier, Herlé Arhan, Michel Lutjeharms, Johann R. E. 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) Department of Oceanography Cape Town University of Cape Town 2003-07 https://hal.science/hal-00271267 https://doi.org/10.1016/S0967-0637(03)00071-2 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/S0967-0637(03)00071-2 hal-00271267 https://hal.science/hal-00271267 doi:10.1016/S0967-0637(03)00071-2 ISSN: 0967-0637 Deep Sea Research Part I: Oceanographic Research Papers https://hal.science/hal-00271267 Deep Sea Research Part I: Oceanographic Research Papers, 2003, 50 (7), pp.863-887. ⟨10.1016/S0967-0637(03)00071-2⟩ Equatorial Atlantic South Atlantic Circulation Current Hydrography [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2003 ftunivnantes https://doi.org/10.1016/S0967-0637(03)00071-2 2023-02-08T06:16:01Z International audience The upper-layer circulation in the eastern basin of the South Atlantic was studied from hydrographic and direct velocity measurements along WOCE lines A11, A13 and A14. A13 and A14 provide quasi-meridional samplings of the equatorial, subequatorial and subtropical circulation regimes. A13 was carried out along the African coast at about 600 km offshore from it, and A14 along the nominal longitude 9°W. A11 intersects the Cape Basin between 46°S in the west and 30°S in the east. Transport estimates were derived from direct velocity measurements and a box inverse model. In the equatorial eastern Atlantic, the Equatorial Undercurrent (EUC) transport decreases from 25×106 m3 s−1 at 9°W to 13×106 m3 s−1 at 5°E. Re-circulations of the EUC into the northern and equatorial branches of the South Equatorial Current (SEC) are evidenced at 5°E and quantified. In the tropical Atlantic, we estimate 7.5×106 and 4.2×106 m3 s−1 for the transports at 9°W of the South Equatorial Undercurrent (SEUC) and South Equatorial Countercurrent (SECC), respectively. Both the SEUC and SECC extend vertically down to intermediate depths and contribute to the northern limb of the Angola Gyre. The Angola Current transport is estimated to be 16±5×106 m3 s−1 for σ1<32.1 at 13°S. South of the Angola Gyre, the transports show an apparent cyclonic circulation, developed mostly at the intermediate level. The water mass properties suggest that it is, at least partially, a re-circulation of the Benguela Current. Further south and for the subtropical gyre, we estimate 10±5×106 m3 s−1 for the transport of the South Atlantic Current across 9°W and 28±4×106 m3 s−1 for the transport of the Benguela Current at 10°E for σ1<32.1. Article in Journal/Newspaper South Atlantic Ocean Université de Nantes: HAL-UNIV-NANTES Deep Sea Research Part I: Oceanographic Research Papers 50 7 863 887 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Equatorial Atlantic South Atlantic Circulation Current Hydrography [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
Equatorial Atlantic South Atlantic Circulation Current Hydrography [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Mercier, Herlé Arhan, Michel Lutjeharms, Johann R. E. Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
topic_facet |
Equatorial Atlantic South Atlantic Circulation Current Hydrography [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience The upper-layer circulation in the eastern basin of the South Atlantic was studied from hydrographic and direct velocity measurements along WOCE lines A11, A13 and A14. A13 and A14 provide quasi-meridional samplings of the equatorial, subequatorial and subtropical circulation regimes. A13 was carried out along the African coast at about 600 km offshore from it, and A14 along the nominal longitude 9°W. A11 intersects the Cape Basin between 46°S in the west and 30°S in the east. Transport estimates were derived from direct velocity measurements and a box inverse model. In the equatorial eastern Atlantic, the Equatorial Undercurrent (EUC) transport decreases from 25×106 m3 s−1 at 9°W to 13×106 m3 s−1 at 5°E. Re-circulations of the EUC into the northern and equatorial branches of the South Equatorial Current (SEC) are evidenced at 5°E and quantified. In the tropical Atlantic, we estimate 7.5×106 and 4.2×106 m3 s−1 for the transports at 9°W of the South Equatorial Undercurrent (SEUC) and South Equatorial Countercurrent (SECC), respectively. Both the SEUC and SECC extend vertically down to intermediate depths and contribute to the northern limb of the Angola Gyre. The Angola Current transport is estimated to be 16±5×106 m3 s−1 for σ1<32.1 at 13°S. South of the Angola Gyre, the transports show an apparent cyclonic circulation, developed mostly at the intermediate level. The water mass properties suggest that it is, at least partially, a re-circulation of the Benguela Current. Further south and for the subtropical gyre, we estimate 10±5×106 m3 s−1 for the transport of the South Atlantic Current across 9°W and 28±4×106 m3 s−1 for the transport of the Benguela Current at 10°E for σ1<32.1. |
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) Department of Oceanography Cape Town University of Cape Town |
format |
Article in Journal/Newspaper |
author |
Mercier, Herlé Arhan, Michel Lutjeharms, Johann R. E. |
author_facet |
Mercier, Herlé Arhan, Michel Lutjeharms, Johann R. E. |
author_sort |
Mercier, Herlé |
title |
Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
title_short |
Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
title_full |
Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
title_fullStr |
Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
title_full_unstemmed |
Upper-layer circulation in the eastern Equatorial and South Atlantic Ocean in January–March 1995. |
title_sort |
upper-layer circulation in the eastern equatorial and south atlantic ocean in january–march 1995. |
publisher |
HAL CCSD |
publishDate |
2003 |
url |
https://hal.science/hal-00271267 https://doi.org/10.1016/S0967-0637(03)00071-2 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
ISSN: 0967-0637 Deep Sea Research Part I: Oceanographic Research Papers https://hal.science/hal-00271267 Deep Sea Research Part I: Oceanographic Research Papers, 2003, 50 (7), pp.863-887. ⟨10.1016/S0967-0637(03)00071-2⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0967-0637(03)00071-2 hal-00271267 https://hal.science/hal-00271267 doi:10.1016/S0967-0637(03)00071-2 |
op_doi |
https://doi.org/10.1016/S0967-0637(03)00071-2 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
50 |
container_issue |
7 |
container_start_page |
863 |
op_container_end_page |
887 |
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1766200476280291328 |