@MastersThesis{Eidt:2018:InAnEx,
author = "Eidt, Renata Tatsch",
title = "Influ{\^e}ncias de anomalias extratropicais de TSM dos oceanos
Pac{\'{\i}}fico Sul e Atl{\^a}ntico Sul na
precipita{\c{c}}{\~a}o das regi{\~o}es Sul e Centro-Oeste do
Brasil",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2018",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2018-08-29",
keywords = "anomalias de TSM, extremos de precipita{\c{c}}{\~a}o,
Am{\'e}rica do Sul, Pac{\'{\i}}fico Sul, Atl{\^a}ntico Sul,
SST anomalies, precipitation extremes, South America, South
Pacific, South Atlantic.",
abstract = "Condi{\c{c}}{\~o}es de tempo e clima afetam diferentes setores,
dentre eles a agricultura, e a sua previsibilidade {\'e}
extremamente importante para garantia de um manejo adequado do
processo agr{\'{\i}}cola. A variabilidade de
precipita{\c{c}}{\~a}o {\'e} importante para a
produ{\c{c}}{\~a}o agr{\'{\i}}cola, e a disponibilidade de
chuvas {\'e} uma resposta a padr{\~o}es oce{\^a}nicos e
atmosf{\'e}ricos. Uma vari{\'a}vel oce{\^a}nica importante
{\'e} a temperatura da superf{\'{\i}}cie do mar (TSM). No
entanto, apesar do enfoque em estudos anteriores para oceanos
tropicais, as regi{\~o}es extratropicais tamb{\'e}m s{\~a}o
importantes para a modula{\c{c}}{\~a}o do clima, e ainda existem
poucos trabalhos direcionados para essas regi{\~o}es. O objetivo
desta disserta{\c{c}}{\~a}o {\'e} identificar os padr{\~o}es
de anomalias de TSM nas regi{\~o}es extratropicais dos oceanos
Pac{\'{\i}}fico Sul e Atl{\^a}ntico Sul que podem influenciar a
circula{\c{c}}{\~a}o atmosf{\'e}rica, afetando a
precipita{\c{c}}{\~a}o em {\'a}reas agr{\'{\i}}colas do
Brasil. O estudo foi feito utilizando-se uma escala de tempo
mensal no per{\'{\i}}odo de 1979 a 2010, com enfoque para os
meses mais relevantes para a agricultura. An{\'a}lises de
correla{\c{c}}{\~a}o e Decomposi{\c{c}}{\~a}o em Valores
Singulares (SVD) de precipita{\c{c}}{\~a}o na Am{\'e}rica do
Sul e TSM nos dois oceanos permitiram a identifica{\c{c}}{\~o}es
de regi{\~o}es oce{\^a}nicas relacionadas. Extremos secos e
chuvosos no Sul e Centro-Oeste do Brasil foram identificados
atrav{\'e}s do {\'{\I}}ndice de Precipita{\c{c}}{\~a}o
Normalizado (SPI) para an{\'a}lise de compostos. Os resultados
mostraram que a precipita{\c{c}}{\~a}o no Sul do Brasil
est{\'a} associada a um dipolo de anomalias de TSM no Oceano
Pac{\'{\i}}fico Sul. Anomalias positivas (negativas) de TSM no
sudeste e negativas (positivas) no noroeste deste oceano foram
observadas quando h{\'a} aumento (redu{\c{c}}{\~a}o) de chuvas
no Sul do Brasil, principalmente no per{\'{\i}}odo de Outubro a
Dezembro. Casos chuvosos (secos) nessa regi{\~a}o tamb{\'e}m
apresentaram rela{\c{c}}{\~a}o com um dipolo de TSM no
Atl{\^a}ntico Sudoeste, quando este apresentou anomalias
positivas (negativas) no norte e negativas (positivas) no sul. A
{\'a}rea na regi{\~a}o Centro-Oeste apresentou um padr{\~a}o
misto de precipita{\c{c}}{\~a}o, com mesmo sinal de anomalias da
regi{\~a}o Sul na parte sul e anomalias opostas na parte norte da
{\'a}rea. Assim, as an{\'a}lises de correla{\c{c}}{\~a}o
n{\~a}o apresentaram um padr{\~a}o bem definido. Por{\'e}m, nos
compostos, o padr{\~a}o de precipita{\c{c}}{\~a}o apresenta
anomalias opostas {\`a} regi{\~a}o Sul, e uma influ{\^e}ncia
maior do Oceano Atl{\^a}ntico e do fluxo de umidade. A partir dos
centros de dipolo identificados no Pac{\'{\i}}fico Sul e
Atl{\^a}ntico Sul, foram criados {\'{\i}}ndices baseados na
diferen{\c{c}}a de anomalia de TSM entre eles com o intuito de
contribuir para identifica{\c{c}}{\~a}o de extremos de
precipita{\c{c}}{\~a}o nas regi{\~o}es de estudo. As anomalias
de TSM no Oceano Pac{\'{\i}}fico Sul estiveram associadas a
mudan{\c{c}}as na dire{\c{c}}{\~a}o das correntes
oce{\^a}nicas, as quais sofrem a{\c{c}}{\~a}o da
circula{\c{c}}{\~a}o atmosf{\'e}rica. An{\'a}lises de
vari{\'a}veis atmosf{\'e}ricas e oce{\^a}nicas indicaram a
intera{\c{c}}{\~a}o oceano-atmosfera com influ{\^e}ncia nos
centros de a{\c{c}}{\~a}o dos trens de onda na atmosfera que
afetam a Am{\'e}rica do Sul. ABSTRACT: Weather and climate
conditions affect different sectors, including agriculture, and
their predictability is extremely important for management.
Precipitation is important for agriculture production, and
rainfall variability depends on oceanic and atmospheric patterns.
Sea surface temperature (SST) is an important oceanic variable.
However, even though previous studies have focused on tropical
oceans to analyze the role of oceans on the atmosphere,
extratropical regions are also important for climate modulation,
and its importance is still not completely understood. The
objective of this study is to identify SST anomalies patterns in
extratropical South Pacific and South Atlantic Oceans that may
influence atmospheric circulation, affecting precipitation in
agricultural areas in Brazil. The study was based on a monthly
timescale from 1979 to 2010, focusing on important months for
agriculture. Correlation and Singular Value Decomposition (SVD)
analysis using precipitation in South America and SST in both
oceans allowed the identification of related oceanic regions.
Extreme dry and wet events in the south and center of Brazil were
identified using the Standardized Precipitation Index (SPI) for a
composites analysis. Results show that precipitation in southern
Brazil is associated with a dipole of SST anomalies in South
Pacific Ocean, as well as in South Atlantic Ocean, with a greater
influence of the former. In the Pacific Ocean, positive (negative)
SST anomalies in the southeast and negative (positive) SST
anomalies in the northwest were observed to increase (decrease)
rainfall over southern Brazil, mainly from October to December.
Wet (dry) events in this region also showed relations to a SST
dipole in Southwestern Atlantic, when there were positive
(negative) anomalies in the north and negative (positive)
anomalies in the south. The central region had a mixed
precipitation pattern, with the same signal of the southern region
in the south and opposite anomalies in the north. Therefore, there
was not a well defined configuration in the correlation analysis.
However, in the composites, the precipitation pattern shows
anomalies opposed to the southern region, and a stronger influence
from the Atlantic Ocean and moisture flux. Based on the centers of
dipoles identified for South Pacific and South Atlantic, indices
calculated by the difference between SST anomalies were developed.
These indices may contribute to identify precipitation extremes in
the study areas. SST anomalies in South Pacific were associated
with changes in the direction of ocean currents, which are
affected by the atmospheric circulation. Analysis of atmospheric
and ocean variables indicated oceanatmosphere interaction with
influence on the centers of action of wave trains in the
atmosphere that affect South America.",
committee = "Pezzi, Luciano Ponzi (presidente) and Cavalcanti, Iracema Fonseca
de Albuquerque (orientadora) and Ambrizzi, T{\'e}rcio",
englishtitle = "Influence of extratropial SST anomalies in South Pacific and South
Atlantic Oceans on precipitation over southern and central
Brazil",
language = "pt",
pages = "163",
ibi = "8JMKD3MGP3W34R/3RLBLHL",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3RLBLHL",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}