Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders
Autor(a) principal: | |
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Data de Publicação: | 2022 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da USP |
Texto Completo: | https://doi.org/10.11606/D.21.2022.tde-22092022-151013 |
Resumo: | Off southeastern Brazil, a unique first-mode-like baroclinic jet is observed above the continental slope: the southward flowing Brazil Current (BC) which occupies the upper 200-300 m, and the northward flowing Intermediate Western Boundary Current (IWBC) which spans from ~200-300 m to ~1800 m. Between 22° and 23°S, the BC-IWBC jet develops recurrent cyclonic meanders that grow quasi-stationarily via baroclinic instability. Such meanders enhance the open-ocean primary productivity and are of societal importance as they are located in a region rich in oil and gas where oil-spill accidents have already happened. Here, we aim to further explore the processes responsible for triggering the formation of these mesoscale eddies by adding the submesoscale component to the hydrodynamic scenario. To address this, a 2-km resolution numerical simulation is performed with CROCO. Our results indicate that incoming anticyclones reach the slope upstream of separation regions and generate submesoscale barotropic shear instability that trigger the meanders\' formation. Subsequently, this process generates submesoscale cyclones that contribute, along with baroclinic instability, to the meanders\' growth resulting in a submesoscale-mesoscale inverse cascade. Lastly, as the mesoscale cyclones grow, they interact with the slope generating anticyclonic submesoscale vortices and filaments that are inertially and symmetrically unstable. |
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info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesis Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders Instabilidades de cisalhamento em submesoescala associadas a interação de meandros da Corrente do Brasil com a topografia 2022-04-29Ilson Carlos Almeida da SilveiraChristian BuckinghamAmit TandonCaique Dias LukoUniversidade de São PauloOceanografiaUSPBR Barotropic Instability Brazil Current Cape Frio Cyclone Cape São Tomé Cyclone Cascata Inversa Ciclone de Cabo de São Tomé Ciclone de Cabo Frio Corrente do Brasil Instabilidade Barotrópica Inverse cascade Submesoscale Coherent Vortices Vórtices Coerentes de Submesoescala Off southeastern Brazil, a unique first-mode-like baroclinic jet is observed above the continental slope: the southward flowing Brazil Current (BC) which occupies the upper 200-300 m, and the northward flowing Intermediate Western Boundary Current (IWBC) which spans from ~200-300 m to ~1800 m. Between 22° and 23°S, the BC-IWBC jet develops recurrent cyclonic meanders that grow quasi-stationarily via baroclinic instability. Such meanders enhance the open-ocean primary productivity and are of societal importance as they are located in a region rich in oil and gas where oil-spill accidents have already happened. Here, we aim to further explore the processes responsible for triggering the formation of these mesoscale eddies by adding the submesoscale component to the hydrodynamic scenario. To address this, a 2-km resolution numerical simulation is performed with CROCO. Our results indicate that incoming anticyclones reach the slope upstream of separation regions and generate submesoscale barotropic shear instability that trigger the meanders\' formation. Subsequently, this process generates submesoscale cyclones that contribute, along with baroclinic instability, to the meanders\' growth resulting in a submesoscale-mesoscale inverse cascade. Lastly, as the mesoscale cyclones grow, they interact with the slope generating anticyclonic submesoscale vortices and filaments that are inertially and symmetrically unstable. Ao largo da costa sudeste brasileira, um jato de primeiro modo baroclínico é observado acima do talude continental: a Corrente do Brasil (CB) que escoa para o sul e ocupa os primeiros 200-300 m de coluna d\'água, e a Corrente de Contorno Intermediária (CCI) que escoa para o norte e se estende de ~200-300 m a ~1800 m. Entre 22° e 23°S, o jato CB-CCI desenvolve recorrentes meandros ciclônicos que crescem quase-estacionariamente via instabilidade baroclínica. Estes meandros aumentam a produtividade primária no oceano aberto e são importantes para a sociedade, já que se formam em uma região rica em petróleo e gás, onde já ocorreram acidentes de derramamento de óleo. Neste estudo, pretendemos explorar os processos responsáveis por desencadear a formação desses vórtices de mesoescala, adicionando a componente de submesoescala ao cenário hidrodinâmico. Para isso, uma simulação numérica de resolução de 2 km é realizada com o modelo CROCO. Os resultados indicam que anticiclones vindos de leste atingem o talude a montante de regiões de separação, e geram instabilidade barotrópica de submesoescala que desencadeia a formação dos meandros. Posteriormente, ciclones de submesoescala são gerados e contribuem, juntamente com a instabilidade baroclínica, para o crescimento dos meandros em uma cascata inversa da submesoescala para a mesoescala. Por fim, à medida que os ciclones de mesoescala crescem, eles interagem com o talude e geram vórtices anticiclônicos de submesoescala e filamentos que são inercial- e simetricamente instáveis. https://doi.org/10.11606/D.21.2022.tde-22092022-151013info:eu-repo/semantics/openAccessengreponame:Biblioteca Digital de Teses e Dissertações da USPinstname:Universidade de São Paulo (USP)instacron:USP2023-12-21T19:54:32Zoai:teses.usp.br:tde-22092022-151013Biblioteca Digital de Teses e Dissertaçõeshttp://www.teses.usp.br/PUBhttp://www.teses.usp.br/cgi-bin/mtd2br.plvirginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.bropendoar:27212023-12-22T13:09:27.367454Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false |
dc.title.en.fl_str_mv |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
dc.title.alternative.pt.fl_str_mv |
Instabilidades de cisalhamento em submesoescala associadas a interação de meandros da Corrente do Brasil com a topografia |
title |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
spellingShingle |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders Caique Dias Luko |
title_short |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
title_full |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
title_fullStr |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
title_full_unstemmed |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
title_sort |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
author |
Caique Dias Luko |
author_facet |
Caique Dias Luko |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Ilson Carlos Almeida da Silveira |
dc.contributor.referee1.fl_str_mv |
Christian Buckingham |
dc.contributor.referee2.fl_str_mv |
Amit Tandon |
dc.contributor.author.fl_str_mv |
Caique Dias Luko |
contributor_str_mv |
Ilson Carlos Almeida da Silveira Christian Buckingham Amit Tandon |
description |
Off southeastern Brazil, a unique first-mode-like baroclinic jet is observed above the continental slope: the southward flowing Brazil Current (BC) which occupies the upper 200-300 m, and the northward flowing Intermediate Western Boundary Current (IWBC) which spans from ~200-300 m to ~1800 m. Between 22° and 23°S, the BC-IWBC jet develops recurrent cyclonic meanders that grow quasi-stationarily via baroclinic instability. Such meanders enhance the open-ocean primary productivity and are of societal importance as they are located in a region rich in oil and gas where oil-spill accidents have already happened. Here, we aim to further explore the processes responsible for triggering the formation of these mesoscale eddies by adding the submesoscale component to the hydrodynamic scenario. To address this, a 2-km resolution numerical simulation is performed with CROCO. Our results indicate that incoming anticyclones reach the slope upstream of separation regions and generate submesoscale barotropic shear instability that trigger the meanders\' formation. Subsequently, this process generates submesoscale cyclones that contribute, along with baroclinic instability, to the meanders\' growth resulting in a submesoscale-mesoscale inverse cascade. Lastly, as the mesoscale cyclones grow, they interact with the slope generating anticyclonic submesoscale vortices and filaments that are inertially and symmetrically unstable. |
publishDate |
2022 |
dc.date.issued.fl_str_mv |
2022-04-29 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://doi.org/10.11606/D.21.2022.tde-22092022-151013 |
url |
https://doi.org/10.11606/D.21.2022.tde-22092022-151013 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade de São Paulo |
dc.publisher.program.fl_str_mv |
Oceanografia |
dc.publisher.initials.fl_str_mv |
USP |
dc.publisher.country.fl_str_mv |
BR |
publisher.none.fl_str_mv |
Universidade de São Paulo |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da USP instname:Universidade de São Paulo (USP) instacron:USP |
instname_str |
Universidade de São Paulo (USP) |
instacron_str |
USP |
institution |
USP |
reponame_str |
Biblioteca Digital de Teses e Dissertações da USP |
collection |
Biblioteca Digital de Teses e Dissertações da USP |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP) |
repository.mail.fl_str_mv |
virginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.br |
_version_ |
1794502978651029504 |