Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation
Mesoscale eddies propagate westward across the South Atlantic basin. As they reach the westernmost part of the basin, at approximately 20°S, they interact with a quasi-zonal seamount chain, the Vitória-Trindade Ridge (VTR). The interactions with the local topography lead to submesoscales instabiliti...
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fthzgzmk:oai:publications.hereon.de:50330 2023-06-11T04:16:42+02:00 Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation Lazaneo, C. Calil, P. Tandon, A. da Silveira, I. 2022 https://publications.hereon.de/id/50330 https://publications.hzg.de/id/50330 https://www.hereon.de/imperia/md/content/gkss/zentrale_einrichtungen/bibliothek/journals/2022/lazaneo_50330.pdf en eng AGU https://dx.doi.org/10.1029/2020JC017099 urn:issn:2169-9275 https://publications.hereon.de/id/50330 https://publications.hzg.de/id/50330 https://www.hereon.de/imperia/md/content/gkss/zentrale_einrichtungen/bibliothek/journals/2022/lazaneo_50330.pdf info:eu-repo/semantics/openAccess open_access oa_gruen issn:2169-9275 Lazaneo, C.; Calil, P.; Tandon, A.; da Silveira, I.: Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation. In: Journal of Geophysical Research : Oceans. Vol. 127 (2022) 2, e2020JC017099. (DOI: /10.1029/2020JC017099) info:eu-repo/semantics/article Zeitschrift Artikel 2022 fthzgzmk https://doi.org/10.1029/2020JC017099 2023-05-28T23:25:27Z Mesoscale eddies propagate westward across the South Atlantic basin. As they reach the westernmost part of the basin, at approximately 20°S, they interact with a quasi-zonal seamount chain, the Vitória-Trindade Ridge (VTR). The interactions with the local topography lead to submesoscales instabilities, which ignite the formation of submesoscale coherent vortices (SCVs) such as those described in the present study for the first time in the VTR region. Here, using high-resolution hydrographic and microstructure measurements, we describe the dynamics of two adjacent SCVs wandering through the ridge. We find that the anticyclonic SCVs are characterized by a low potential vorticity and angular momentum signature, and are therefore prone to both centrifugal and symmetric instabilities. This dynamic regime suggests small-scale turbulence is actively cascading energy down to dissipation, diagnosed from turbulent kinetic energy dissipation estimates within one of the SCVs through microstructure measurements. The energy dissipation levels observed within the SCV are two orders of magnitude larger than in surrounding waters. The thermohaline signatures of each SCV reveal homogenized waters in their cores but with small thermohaline anomalies when compared to surrounding waters, suggesting a remote generation site. Here, we argue that such vortices are essential agents for energy dissipation in the ocean. We speculate that the observed SCVs were formed due to mesoscale eddy-topography interaction along the VTR and advected by the meandering South Equatorial Current to the location of field observations. Article in Journal/Newspaper South Atlantic Ocean Hereon Publications (Helmholtz-Zentrum) Journal of Geophysical Research: Oceans 127 2 |
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Open Polar |
collection |
Hereon Publications (Helmholtz-Zentrum) |
op_collection_id |
fthzgzmk |
language |
English |
description |
Mesoscale eddies propagate westward across the South Atlantic basin. As they reach the westernmost part of the basin, at approximately 20°S, they interact with a quasi-zonal seamount chain, the Vitória-Trindade Ridge (VTR). The interactions with the local topography lead to submesoscales instabilities, which ignite the formation of submesoscale coherent vortices (SCVs) such as those described in the present study for the first time in the VTR region. Here, using high-resolution hydrographic and microstructure measurements, we describe the dynamics of two adjacent SCVs wandering through the ridge. We find that the anticyclonic SCVs are characterized by a low potential vorticity and angular momentum signature, and are therefore prone to both centrifugal and symmetric instabilities. This dynamic regime suggests small-scale turbulence is actively cascading energy down to dissipation, diagnosed from turbulent kinetic energy dissipation estimates within one of the SCVs through microstructure measurements. The energy dissipation levels observed within the SCV are two orders of magnitude larger than in surrounding waters. The thermohaline signatures of each SCV reveal homogenized waters in their cores but with small thermohaline anomalies when compared to surrounding waters, suggesting a remote generation site. Here, we argue that such vortices are essential agents for energy dissipation in the ocean. We speculate that the observed SCVs were formed due to mesoscale eddy-topography interaction along the VTR and advected by the meandering South Equatorial Current to the location of field observations. |
format |
Article in Journal/Newspaper |
author |
Lazaneo, C. Calil, P. Tandon, A. da Silveira, I. |
spellingShingle |
Lazaneo, C. Calil, P. Tandon, A. da Silveira, I. Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
author_facet |
Lazaneo, C. Calil, P. Tandon, A. da Silveira, I. |
author_sort |
Lazaneo, C. |
title |
Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
title_short |
Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
title_full |
Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
title_fullStr |
Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
title_full_unstemmed |
Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation |
title_sort |
submesoscale coherent vortices in the south atlantic ocean: a pathway for energy dissipation |
publisher |
AGU |
publishDate |
2022 |
url |
https://publications.hereon.de/id/50330 https://publications.hzg.de/id/50330 https://www.hereon.de/imperia/md/content/gkss/zentrale_einrichtungen/bibliothek/journals/2022/lazaneo_50330.pdf |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
issn:2169-9275 Lazaneo, C.; Calil, P.; Tandon, A.; da Silveira, I.: Submesoscale Coherent Vortices in the South Atlantic Ocean: A Pathway for Energy Dissipation. In: Journal of Geophysical Research : Oceans. Vol. 127 (2022) 2, e2020JC017099. (DOI: /10.1029/2020JC017099) |
op_relation |
https://dx.doi.org/10.1029/2020JC017099 urn:issn:2169-9275 https://publications.hereon.de/id/50330 https://publications.hzg.de/id/50330 https://www.hereon.de/imperia/md/content/gkss/zentrale_einrichtungen/bibliothek/journals/2022/lazaneo_50330.pdf |
op_rights |
info:eu-repo/semantics/openAccess open_access oa_gruen |
op_doi |
https://doi.org/10.1029/2020JC017099 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
127 |
container_issue |
2 |
_version_ |
1768375201982054400 |