Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection
The equatorial retroflection of the North Brazil Current (NBC) into the Equatorial Undercurrent (EUC) and its posterior tropical recirculation is a major regulator for the returning limb of the Atlantic Meridional Overturning Circulation. Indeed, most surface and thermocline NBC waters retroflect at...
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Centro Oceanográfico de Canarias
2022
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Online Access: | http://hdl.handle.net/10508/15698 https://doi.org/10.1029/2021JC018150 |
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ftieo:oai:repositorio.ieo.es:10508/15698 2023-05-15T17:31:40+02:00 Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection Vallès-Casanova, I. (Ignasi) Fraile-Nuez, E. (Eugenio) Martín-Rey, M. (Marta) van Sebille, E. (Erik) Cabré, A. (Anna) Olivé-Abelló, A. (Anna) Pelegrí, J.L. (Josep L.) 2022-04-16 http://hdl.handle.net/10508/15698 https://doi.org/10.1029/2021JC018150 eng eng Centro Oceanográfico de Canarias 0148-0227 http://hdl.handle.net/10508/15698 Journal of Geophysical Research-Oceans, 127. 2022: 1-21 doi:10.1029/2021JC018150 Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ openAccess CC-BY-NC-ND zonal distribution boundary currents western boundary currents overturn thermocline article 2022 ftieo https://doi.org/10.1029/2021JC018150 2022-09-20T23:46:50Z The equatorial retroflection of the North Brazil Current (NBC) into the Equatorial Undercurrent (EUC) and its posterior tropical recirculation is a major regulator for the returning limb of the Atlantic Meridional Overturning Circulation. Indeed, most surface and thermocline NBC waters retroflect at the equator all the way into the central and eastern Atlantic Ocean, before they recirculate back through the tropics to the western boundary. Here, we use cruise data in the western equatorial Atlantic during April 2010 and reanalysis time series for the equatorial and tropical waters in both hemispheres in order to explore the recirculation pathways and transport variability. During the 1998–2016 period, the annual-mean EUC transports 15.1 ± 1.3 Sv at 32°W, with 2.8 ± 0.4 Sv from the North Atlantic and 11.4 ± 1.3 Sv from the South Atlantic. At 32°W most of the total EUC transport comes from the western boundary retroflection south of 3°N (7.2 ± 0.9 Sv), a substantial fraction retroflects north of 3°N (5.6 ± 0.4 Sv), and the remaining flow (2.3 Sv) joins through the interior basin. The South Atlantic subtropical waters feed the EUC at all thermocline depths while the North Atlantic and South Atlantic tropical waters do so at the surface and upper-thermocline levels. The EUC transport at 32°W has a pronounced seasonality, with spring and fall maxima and a range of 8.8 Sv. The 18 yr of reanalysis data shows a weak yet significant correlation with an Atlantic Niño index, and also suggests an enhanced contribution from the South Atlantic tropical waters during 2008–2016 as compared with 1997–2007 En prensa 3,174 Article in Journal/Newspaper North Atlantic Instituto Español de Oceanografía: e-IEO Journal of Geophysical Research: Oceans 127 5 |
institution |
Open Polar |
collection |
Instituto Español de Oceanografía: e-IEO |
op_collection_id |
ftieo |
language |
English |
topic |
zonal distribution boundary currents western boundary currents overturn thermocline |
spellingShingle |
zonal distribution boundary currents western boundary currents overturn thermocline Vallès-Casanova, I. (Ignasi) Fraile-Nuez, E. (Eugenio) Martín-Rey, M. (Marta) van Sebille, E. (Erik) Cabré, A. (Anna) Olivé-Abelló, A. (Anna) Pelegrí, J.L. (Josep L.) Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
topic_facet |
zonal distribution boundary currents western boundary currents overturn thermocline |
description |
The equatorial retroflection of the North Brazil Current (NBC) into the Equatorial Undercurrent (EUC) and its posterior tropical recirculation is a major regulator for the returning limb of the Atlantic Meridional Overturning Circulation. Indeed, most surface and thermocline NBC waters retroflect at the equator all the way into the central and eastern Atlantic Ocean, before they recirculate back through the tropics to the western boundary. Here, we use cruise data in the western equatorial Atlantic during April 2010 and reanalysis time series for the equatorial and tropical waters in both hemispheres in order to explore the recirculation pathways and transport variability. During the 1998–2016 period, the annual-mean EUC transports 15.1 ± 1.3 Sv at 32°W, with 2.8 ± 0.4 Sv from the North Atlantic and 11.4 ± 1.3 Sv from the South Atlantic. At 32°W most of the total EUC transport comes from the western boundary retroflection south of 3°N (7.2 ± 0.9 Sv), a substantial fraction retroflects north of 3°N (5.6 ± 0.4 Sv), and the remaining flow (2.3 Sv) joins through the interior basin. The South Atlantic subtropical waters feed the EUC at all thermocline depths while the North Atlantic and South Atlantic tropical waters do so at the surface and upper-thermocline levels. The EUC transport at 32°W has a pronounced seasonality, with spring and fall maxima and a range of 8.8 Sv. The 18 yr of reanalysis data shows a weak yet significant correlation with an Atlantic Niño index, and also suggests an enhanced contribution from the South Atlantic tropical waters during 2008–2016 as compared with 1997–2007 En prensa 3,174 |
format |
Article in Journal/Newspaper |
author |
Vallès-Casanova, I. (Ignasi) Fraile-Nuez, E. (Eugenio) Martín-Rey, M. (Marta) van Sebille, E. (Erik) Cabré, A. (Anna) Olivé-Abelló, A. (Anna) Pelegrí, J.L. (Josep L.) |
author_facet |
Vallès-Casanova, I. (Ignasi) Fraile-Nuez, E. (Eugenio) Martín-Rey, M. (Marta) van Sebille, E. (Erik) Cabré, A. (Anna) Olivé-Abelló, A. (Anna) Pelegrí, J.L. (Josep L.) |
author_sort |
Vallès-Casanova, I. (Ignasi) |
title |
Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
title_short |
Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
title_full |
Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
title_fullStr |
Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
title_full_unstemmed |
Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
title_sort |
water mass transports and pathways in the north brazil- equatorial undercurrent retroflection |
publisher |
Centro Oceanográfico de Canarias |
publishDate |
2022 |
url |
http://hdl.handle.net/10508/15698 https://doi.org/10.1029/2021JC018150 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
0148-0227 http://hdl.handle.net/10508/15698 Journal of Geophysical Research-Oceans, 127. 2022: 1-21 doi:10.1029/2021JC018150 |
op_rights |
Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ openAccess |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1029/2021JC018150 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
127 |
container_issue |
5 |
_version_ |
1766129356066783232 |