The South Atlantic circulation between 34.5°S, 24°S and above the Mid‐Atlantic Ridge from an inverse box model

Arumí‐Planas, Cristina; Pérez‐Hernández, María Dolores; Pelegrí, Josep L.; Vélez‐Belchí, Pedro; Emelianov, Mikhail; Caínzos, Verónica; Cana, Luis; Firing, Yvonne L. ORCID: https://orcid.org/0000-0002-3640-3974; García‐Weil, Luis; Santana‐Toscano, Daniel; Hernández‐Guerra, Alonso. 2023 The South Atlantic circulation between 34.5°S, 24°S and above the Mid‐Atlantic Ridge from an inverse box model. Journal of Geophysical Research: Oceans, 128 (5). https://doi.org/10.1029/2022JC019614

Before downloading, please read NORA policies.

Preview

Text
JGR Oceans - 2023 - Arum ‐Planas - The South Atlantic Circulation Between 34 5 S 24 S and Above the Mid‐Atlantic Ridge.pdf - Published Version
Available under License Creative Commons Attribution 4.0.
Download (3MB) | Preview

Official URL: http://dx.doi.org/10.1029/2022JC019614

Abstract/Summary

The South Atlantic Ocean plays a key role in the heat exchange of the climate system, as it hosts the returning flow of the Atlantic Meridional Overturning Circulation (AMOC). To gain insights on this role, using data from three hydrographic cruises conducted in the South Atlantic Subtropical gyre at 34.5°S, 24°S, and 10°W, we identify water masses and compute absolute geostrophic circulation using inverse modeling. In the upper layers, the currents describe the South Atlantic anticyclonic gyre with the northwest flowing Benguela Current (26.3 ± 2.0 Sv at 34.5°S, and 21.2 ± 1.8 Sv at 24°S) flowing above the Mid-Atlantic Ridge (MAR) between 22.4°S and 28.4°S (−19.2 ± 1.4 Sv), and the southward flowing Brazil Current (−16.5 ± 1.3 Sv at 34.5°S, and −7.3 ± 0.9 Sv at 24°S); the deep layers feature the southward transports of Deep Western Boundary Current (−13.9 ± 3.0 Sv at 34.5°S, and −8.7 ± 3.8 Sv at 24°S) and Deep Eastern Boundary Current (−15.1 ± 3.5 Sv at 34.5°S, and −16.3 ± 4.7 Sv at 24°S), with the interbasin west-to-east flow close to 24°S (7.5 ± 4.4 Sv); the abyssal waters present northward mass transports through the Argentina Basin (5.6 ± 1.1 Sv at 34.5°S, and 5.8 ± 1.5 Sv at 24°S) and Cape Basin (8.6 ± 3.5 Sv at 34.5°S–3.0 ± 0.8 Sv at 24°S) before returning southward (−2.2 ± 0.7 Sv at 24°S to −7.9 ± 3.6 Sv at 34.5°S), without any interbasin exchange across the MAR. In addition, we compute the upper AMOC strength (14.8 ± 1.0 and 17.5 ± 0.9 Sv), the equatorward heat transport (0.30 ± 0.05 and 0.80 ± 0.05 PW), and the freshwater flux (0.18 ± 0.02 and −0.07 ± 0.02 Sv) at 34.5°S and 24°S, respectively.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1029/2022JC019614
ISSN:	2169-9275
Date made live:	07 Jun 2023 12:49 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/534894

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1029/2022JC019614

ISSN:

2169-9275

Date made live:

07 Jun 2023 12:49 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/534894