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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Online Access: | http://hdl.handle.net/10508/15698 http://hdl.handle.net/10261/317763 https://doi.org/10.1029/2021JC018150 |
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ftcsic:oai:digital.csic.es:10261/317763 2024-02-11T10:06:19+01:00 Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection Vallès-Casanova, Ignasi Fraile-Nuez, Eugenio Martín-Rey, Marta van Sebille, Erik Cabré, Anna Olivé-Abelló, Anna Pelegrí, J.L. 2022-04-16 http://hdl.handle.net/10508/15698 http://hdl.handle.net/10261/317763 https://doi.org/10.1029/2021JC018150 en eng Centro Oceanográfico de Canarias AM Journal of Geophysical Research-Oceans, 127. 2022: 1-21 0148-0227 http://hdl.handle.net/10508/15698 http://hdl.handle.net/10261/317763 doi:10.1029/2021JC018150 50033 open Medio Marino Centro Oceanográfico de Canarias zonal distribution boundary currents western boundary currents overturn thermocline research article 2022 ftcsic https://doi.org/10.1029/2021JC018150 2024-01-16T11:44:50Z 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 SI Article in Journal/Newspaper North Atlantic Digital.CSIC (Spanish National Research Council) Journal of Geophysical Research: Oceans 127 5 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Medio Marino Centro Oceanográfico de Canarias zonal distribution boundary currents western boundary currents overturn thermocline |
spellingShingle |
Medio Marino Centro Oceanográfico de Canarias zonal distribution boundary currents western boundary currents overturn thermocline Vallès-Casanova, Ignasi Fraile-Nuez, Eugenio Martín-Rey, Marta van Sebille, Erik Cabré, Anna Olivé-Abelló, Anna Pelegrí, J.L. Water Mass Transports and Pathways in the North Brazil- Equatorial Undercurrent Retroflection |
topic_facet |
Medio Marino Centro Oceanográfico de Canarias 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 SI |
format |
Article in Journal/Newspaper |
author |
Vallès-Casanova, Ignasi Fraile-Nuez, Eugenio Martín-Rey, Marta van Sebille, Erik Cabré, Anna Olivé-Abelló, Anna Pelegrí, J.L. |
author_facet |
Vallès-Casanova, Ignasi Fraile-Nuez, Eugenio Martín-Rey, Marta van Sebille, Erik Cabré, Anna Olivé-Abelló, Anna Pelegrí, J.L. |
author_sort |
Vallès-Casanova, 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 |
publishDate |
2022 |
url |
http://hdl.handle.net/10508/15698 http://hdl.handle.net/10261/317763 https://doi.org/10.1029/2021JC018150 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Centro Oceanográfico de Canarias AM Journal of Geophysical Research-Oceans, 127. 2022: 1-21 0148-0227 http://hdl.handle.net/10508/15698 http://hdl.handle.net/10261/317763 doi:10.1029/2021JC018150 50033 |
op_rights |
open |
op_doi |
https://doi.org/10.1029/2021JC018150 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
127 |
container_issue |
5 |
_version_ |
1790603953762729984 |