Topographically-generated submesoscale shear instabilities associated with Brazil Current meanders

Detalhes bibliográficos
Ano de defesa: 2022
Autor(a) principal: Luko, Caique Dias
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: eng
Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
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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spelling 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
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