Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders
Ano de defesa: | 2022 |
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Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Dissertação |
Tipo de acesso: | Acesso aberto |
Idioma: | eng |
Instituição de defesa: |
Biblioteca Digitais de Teses e Dissertações da USP
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Programa de Pós-Graduação: |
Não Informado pela instituição
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Departamento: |
Não Informado pela instituição
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País: |
Não Informado pela instituição
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Palavras-chave em Português: | |
Link de acesso: | https://www.teses.usp.br/teses/disponiveis/21/21135/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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Biblioteca Digital de Teses e Dissertações da USP |
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Topographically-generated submesoscale shear instabilities associated with Brazil Current meandersInstabilidades de cisalhamento em submesoescala associadas a interação de meandros da Corrente do Brasil com a topografiaBarotropic InstabilityBrazil CurrentCape Frio CycloneCape São Tomé CycloneCascata InversaCiclone de Cabo de São ToméCiclone de Cabo FrioCorrente do BrasilInstabilidade BarotrópicaInverse cascadeSubmesoscale Coherent VorticesVórtices Coerentes de SubmesoescalaOff 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.Biblioteca Digitais de Teses e Dissertações da USPSilveira, Ilson Carlos Almeida daLuko, Caique Dias2022-04-29info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttps://www.teses.usp.br/teses/disponiveis/21/21135/tde-22092022-151013/reponame:Biblioteca Digital de Teses e Dissertações da USPinstname:Universidade de São Paulo (USP)instacron:USPLiberar o conteúdo para acesso público.info:eu-repo/semantics/openAccesseng2022-10-05T18:36:43Zoai: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:27212022-10-05T18:36:43Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false |
dc.title.none.fl_str_mv |
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 |
title |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders |
spellingShingle |
Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders Luko, Caique Dias 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 |
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 |
Luko, Caique Dias |
author_facet |
Luko, Caique Dias |
author_role |
author |
dc.contributor.none.fl_str_mv |
Silveira, Ilson Carlos Almeida da |
dc.contributor.author.fl_str_mv |
Luko, Caique Dias |
dc.subject.por.fl_str_mv |
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 |
topic |
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 |
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.none.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://www.teses.usp.br/teses/disponiveis/21/21135/tde-22092022-151013/ |
url |
https://www.teses.usp.br/teses/disponiveis/21/21135/tde-22092022-151013/ |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
|
dc.rights.driver.fl_str_mv |
Liberar o conteúdo para acesso público. info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Liberar o conteúdo para acesso público. |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.coverage.none.fl_str_mv |
|
dc.publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
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_ |
1809092048665444352 |