Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin

Detalhes bibliográficos
Autor(a) principal: López, Katherine Lisbeth Ccoica
Data de Publicação: 2020
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
Texto Completo: https://www.teses.usp.br/teses/disponiveis/14/14133/tde-27072020-135440/
Resumo: This study provides a detailed analysis, in the interannual time-scale, of the influence of the tropical Pacific and the Atlantic Ocean in the precipitation regime over South America, with a focus on the Amazon Basin. For this purpose, first, monthly sea surface temperature data is used to determine the principal modes of variability in three Atlantic regions: Tropical North Atlantic (TNA), Tropical South Atlantic (TSA), and Subtropical South Atlantic (STSA). These patterns are obtained from Empirical Orthogonal Function (EOF), where the first mode (PC1) of each region explains the interannual variability in high percentage. The PC1 time series also shows SST peaks related to extreme precipitation events in the Amazon Basin. In addition, the Pacific and Atlantic interaction was analyzed by moving correlations and cross-wavelets for the 1880-2017 period, using Pacific indices (E and C index) and the PC1 of each Atlantic region. We found that the Atlantic regions have been coupling and decoupling in specific periods. Likewise, the Pacific and the Atlantic oceans have been shown in-phase or in opposite phase in different periods of time and frequencies. Precipitation from satellite and combined observed-satellite for the 1940-2010 period were used to identify regions influenced by the Pacific and Atlantic SST. The results suggest that different El Niño Southern Oscillation (ENSO) flavors mainly impact precipitation during the onset (October-November) and peak (December-February) of the South America Monsoon System (SAMS). We have also shown that anomalous conditions over the Tropical North and South Atlantic Ocean impact precipitation regimes during the demise (March-April) and the absence of the SAMS (May-September), while the Subtropical South Atlantic impacts in precipitation during the peak and the absence of the SAMS. Additionally, moisture flux, its divergence, and vertical structure over South America and the adjoining oceans were obtained for different conditions of tropical oceans, through the oceanic indices. Results show that anomalous conditions of sea surface temperature in these oceanic regions modify the source and sink regions for atmospheric moisture in all seasons. A reduction in the moisture inflow, mainly in warm tropical Atlantic conditions, could lead to extremely dry periods in central-southern Amazon and the northern La Plata Basin. This effect, indeed, could be even more extreme in tropical South America when it is preceded by the El Niño event. However, contrasted impacts are observed during El Niño years, with rainfall deficit in tropical South America, east of the Andes, and rainfall excess over southeastern South America and northwest of the Andes (northern Peru, coastal Ecuador, and Colombia). These findings provide an analysis that will help to improve adaptation and risk management policies related to impacts of climate variability and change.
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spelling Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon BasinVariabilidade interanual do Atlântico Tropical e sua influência em eventos extremos de precipitaçãoanálise de clusterscluster analysisextreme precipitationíndices oceânicosinterannual SST variabilityinterdecadal SST variabilityoceanic indicesprecipitação extremarainfall variabilityvariabilidade da chuvavariabilidade interanual da SSTvariabilidade interdecadal da SSTThis study provides a detailed analysis, in the interannual time-scale, of the influence of the tropical Pacific and the Atlantic Ocean in the precipitation regime over South America, with a focus on the Amazon Basin. For this purpose, first, monthly sea surface temperature data is used to determine the principal modes of variability in three Atlantic regions: Tropical North Atlantic (TNA), Tropical South Atlantic (TSA), and Subtropical South Atlantic (STSA). These patterns are obtained from Empirical Orthogonal Function (EOF), where the first mode (PC1) of each region explains the interannual variability in high percentage. The PC1 time series also shows SST peaks related to extreme precipitation events in the Amazon Basin. In addition, the Pacific and Atlantic interaction was analyzed by moving correlations and cross-wavelets for the 1880-2017 period, using Pacific indices (E and C index) and the PC1 of each Atlantic region. We found that the Atlantic regions have been coupling and decoupling in specific periods. Likewise, the Pacific and the Atlantic oceans have been shown in-phase or in opposite phase in different periods of time and frequencies. Precipitation from satellite and combined observed-satellite for the 1940-2010 period were used to identify regions influenced by the Pacific and Atlantic SST. The results suggest that different El Niño Southern Oscillation (ENSO) flavors mainly impact precipitation during the onset (October-November) and peak (December-February) of the South America Monsoon System (SAMS). We have also shown that anomalous conditions over the Tropical North and South Atlantic Ocean impact precipitation regimes during the demise (March-April) and the absence of the SAMS (May-September), while the Subtropical South Atlantic impacts in precipitation during the peak and the absence of the SAMS. Additionally, moisture flux, its divergence, and vertical structure over South America and the adjoining oceans were obtained for different conditions of tropical oceans, through the oceanic indices. Results show that anomalous conditions of sea surface temperature in these oceanic regions modify the source and sink regions for atmospheric moisture in all seasons. A reduction in the moisture inflow, mainly in warm tropical Atlantic conditions, could lead to extremely dry periods in central-southern Amazon and the northern La Plata Basin. This effect, indeed, could be even more extreme in tropical South America when it is preceded by the El Niño event. However, contrasted impacts are observed during El Niño years, with rainfall deficit in tropical South America, east of the Andes, and rainfall excess over southeastern South America and northwest of the Andes (northern Peru, coastal Ecuador, and Colombia). These findings provide an analysis that will help to improve adaptation and risk management policies related to impacts of climate variability and change.Este estudo fornece uma análise, em escala de tempo interanual, da influência dos oceanos Pacífico tropical e Atlântico no regime de precipitação na América do Sul, com foco na Bacia Amazônica. Para esse fim, primeiro os dados mensais da temperatura da superfície do mar (SST) são usados para determinar os principais modos de variabilidade em três regiões do Atlântico: Atlântico Tropical Norte (TNA), Atlântico Tropical Sul (TSA) e Atlântico Sul Subtropical (STSA). Esses padrões são obtidos da Função Ortogonal Empírica (EOF), onde o primeiro modo (PC1) de cada região explica a variabilidade interanual em porcentagem alta, além de mostrar os picos de SST relacionados a eventos extremos de precipitação na Bacia Amazônica. Além disso, a interação do Pacífico e Atlântico foi analisada por correlações móveis e ondeletas cruzadas para o período 1880-2017, usando índices do Pacífico (índices E e C) e o PC1 de cada região do Atlântico. Os resultados mostram que as regiões do Atlântico estiveram acopladas e desacopladas em determinados períodos. Da mesma forma, os oceanos Pacífico e Atlântico foram mostrados em fase ou fase oposta em diferentes períodos de tempo e escalas de frequência. Finalmente, a precipitação de dados do satélite e dados combinados (observado e satélite) para o período 1940-2010 foram usados para identificar as regiões onde o SST do Pacífico e do Atlântico influenciam. Os resultados sugerem que os diferentes ingredientes de El Niño Southern Oscillation (ENSO) impactam principalmente na precipitação durante o início (outubro-novembro) e o pico (dezembro-fevereiro) do Sistema de Monção da América do Sul (SAMS). Também é mostrado que condições anômalas sobre o Oceano Atlântico Tropical Norte e Sul afetam os regimes de precipitação durante o final (março-abril) e o período de ausência do SAMS (maio-setembro), enquanto o Atlântico Sul Subtropical afeta a precipitação durante o pico e durante a ausência do SAMS. O fluxo de umidade, sua divergência e a estrutura vertical sobre a América do Sul e os oceanos adjacentes são obtidos para diferentes condições dos oceanos tropicais, através dos índices oceânicos. Os resultados mostram que condições anômalas da temperatura da superfície do mar nessas regiões oceânicas modificam as regiões de fonte e sumidouro da umidade atmosférica em todas as estações. Uma redução no fluxo de umidade, principalmente em condições tropicais quentes do Atlântico, pode levar a períodos extremamente secos no centro-sul da Amazônia e no norte da Bacia da Prata. Esse efeito, de fato, pode ser ainda mais extremo na América do Sul, quando é precedido pelo evento El Niño. No entanto, impactos contrastantes são observados durante os anos do El Niño, com deficit pluviométrico na América do Sul tropical, a leste dos Andes e excesso de chuva no sudeste da América do Sul e noroeste dos Andes (norte do Peru, litoral do Equador e Colômbia). Os resultados fornecem uma análise que ajudará a melhorar as políticas de adaptação e gerenciamento de riscos relacionadas aos impactos da variabilidade e mudança climática.Biblioteca Digitais de Teses e Dissertações da USPHallak, RicardoLópez, Katherine Lisbeth Ccoica2020-06-09info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttps://www.teses.usp.br/teses/disponiveis/14/14133/tde-27072020-135440/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/openAccesseng2020-08-13T00:47:37Zoai:teses.usp.br:tde-27072020-135440Biblioteca 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:27212020-08-13T00:47:37Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false
dc.title.none.fl_str_mv Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
Variabilidade interanual do Atlântico Tropical e sua influência em eventos extremos de precipitação
title Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
spellingShingle Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
López, Katherine Lisbeth Ccoica
análise de clusters
cluster analysis
extreme precipitation
índices oceânicos
interannual SST variability
interdecadal SST variability
oceanic indices
precipitação extrema
rainfall variability
variabilidade da chuva
variabilidade interanual da SST
variabilidade interdecadal da SST
title_short Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
title_full Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
title_fullStr Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
title_full_unstemmed Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
title_sort Interannual variability of Tropical Atlantic and its influence on extreme precipitation events: Focus on the Amazon Basin
author López, Katherine Lisbeth Ccoica
author_facet López, Katherine Lisbeth Ccoica
author_role author
dc.contributor.none.fl_str_mv Hallak, Ricardo
dc.contributor.author.fl_str_mv López, Katherine Lisbeth Ccoica
dc.subject.por.fl_str_mv análise de clusters
cluster analysis
extreme precipitation
índices oceânicos
interannual SST variability
interdecadal SST variability
oceanic indices
precipitação extrema
rainfall variability
variabilidade da chuva
variabilidade interanual da SST
variabilidade interdecadal da SST
topic análise de clusters
cluster analysis
extreme precipitation
índices oceânicos
interannual SST variability
interdecadal SST variability
oceanic indices
precipitação extrema
rainfall variability
variabilidade da chuva
variabilidade interanual da SST
variabilidade interdecadal da SST
description This study provides a detailed analysis, in the interannual time-scale, of the influence of the tropical Pacific and the Atlantic Ocean in the precipitation regime over South America, with a focus on the Amazon Basin. For this purpose, first, monthly sea surface temperature data is used to determine the principal modes of variability in three Atlantic regions: Tropical North Atlantic (TNA), Tropical South Atlantic (TSA), and Subtropical South Atlantic (STSA). These patterns are obtained from Empirical Orthogonal Function (EOF), where the first mode (PC1) of each region explains the interannual variability in high percentage. The PC1 time series also shows SST peaks related to extreme precipitation events in the Amazon Basin. In addition, the Pacific and Atlantic interaction was analyzed by moving correlations and cross-wavelets for the 1880-2017 period, using Pacific indices (E and C index) and the PC1 of each Atlantic region. We found that the Atlantic regions have been coupling and decoupling in specific periods. Likewise, the Pacific and the Atlantic oceans have been shown in-phase or in opposite phase in different periods of time and frequencies. Precipitation from satellite and combined observed-satellite for the 1940-2010 period were used to identify regions influenced by the Pacific and Atlantic SST. The results suggest that different El Niño Southern Oscillation (ENSO) flavors mainly impact precipitation during the onset (October-November) and peak (December-February) of the South America Monsoon System (SAMS). We have also shown that anomalous conditions over the Tropical North and South Atlantic Ocean impact precipitation regimes during the demise (March-April) and the absence of the SAMS (May-September), while the Subtropical South Atlantic impacts in precipitation during the peak and the absence of the SAMS. Additionally, moisture flux, its divergence, and vertical structure over South America and the adjoining oceans were obtained for different conditions of tropical oceans, through the oceanic indices. Results show that anomalous conditions of sea surface temperature in these oceanic regions modify the source and sink regions for atmospheric moisture in all seasons. A reduction in the moisture inflow, mainly in warm tropical Atlantic conditions, could lead to extremely dry periods in central-southern Amazon and the northern La Plata Basin. This effect, indeed, could be even more extreme in tropical South America when it is preceded by the El Niño event. However, contrasted impacts are observed during El Niño years, with rainfall deficit in tropical South America, east of the Andes, and rainfall excess over southeastern South America and northwest of the Andes (northern Peru, coastal Ecuador, and Colombia). These findings provide an analysis that will help to improve adaptation and risk management policies related to impacts of climate variability and change.
publishDate 2020
dc.date.none.fl_str_mv 2020-06-09
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/14/14133/tde-27072020-135440/
url https://www.teses.usp.br/teses/disponiveis/14/14133/tde-27072020-135440/
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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