@MastersThesis{Gomes:2018:AnPaAt,
author = "Gomes, Mariah Sousa",
title = "An{\'a}lise dos padr{\~o}es atmosf{\'e}ricos associados a
eventos secos na bacia Amaz{\^o}nia",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2018",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2018-05-25",
keywords = "Seca, bacia Amaz{\^o}nica, circula{\c{c}}{\~a}o
atmosf{\'e}rica, rean{\'a}lise CFSR, sat{\'e}lite TRMM,
drought, Amazon basin, atmospheric circulation, reanalysis CFSR,
satellite TRMM.",
abstract = "Secas s{\~a}o eventos meteorol{\'o}gicos capazes de causar
graves transtornos socioecon{\^o}micos. Embora sua
defini{\c{c}}{\~a}o varie de acordo com o clima da localidade
afetada e finalidade do estudo, s{\~a}o caracterizadas por um
d{\'e}ficit h{\'{\i}}drico como consequ{\^e}ncia de um
prolongado per{\'{\i}}odo de chuvas inferiores a m{\'e}dia na
{\'a}rea em quest{\~a}o. Na Amaz{\^o}nia, encontra-se a maior
floresta tropical e bacia hidrogr{\'a}fica do mundo, o que faz
dela um bioma de caracter{\'{\i}}sticas peculiares. O ENOS e
aquecimento an{\^o}malo da superf{\'{\i}}cie do ATN impactam
nas condi{\c{c}}{\~o}es atmosf{\'e}ricas da regi{\~a}o, e
consequentemente na variabilidade do seu regime de chuvas.
Recentes estudos investigaram a rela{\c{c}}{\~a}o entre tais
fen{\^o}menos e as secas de 1997-1998, 2005 e 2010, no entanto
alguns aspectos destes epis{\'o}dios ainda n{\~a}o foram
esclarecidos, como as caracter{\'{\i}}sticas da
circula{\c{c}}{\~a}o m{\'e}dia durante os eventos. O presente
estudo tem por objetivos caracterizar os eventos de 1997-1998,
2005 e 2010, identificar a influ{\^e}ncia remota das anomalias de
TSM mencionadas e padr{\~o}es atmosf{\'e}ricos associados, em
espec{\'{\i}}fico as circula{\c{c}}{\~o}es de Hadley e Walker.
Os resultados encontrados permitiram identificar que padr{\~o}es
de circula{\c{c}}{\~a}o zonal an{\^o}malos foram determinantes
para a ocorr{\^e}ncia do evento seco de 1997-1998 uma vez que
houve uma invers{\~a}o da posi{\c{c}}{\~a}o dos ramos
ascendentes e subsidentes da c{\'e}lula de Walker. A componente
meridional tamb{\'e}m determinou as altera{\c{c}}{\~o}es no
regime de chuvas, e suas anomalias provavelmente estiveram
associadas ao enfraquecimento dos ventos Al{\'{\i}}sios. As
condi{\c{c}}{\~o}es secas que culminaram no evento de 2005 foram
determinadas, em sua maior parte, pelas anomalias de
circula{\c{c}}{\~a}o meridional de Hadley, com ramo ascendente
deslocado para nordeste. As anomalias sazonais de
precipita{\c{c}}{\~a}o na bacia Amaz{\^o}nica persistiram
principalmente durante a esta{\c{c}}{\~a}o seca de 2004 e 2005,
no entanto observou-se intensas anomalias positivas de movimento
vertical sobre o ATN na esta{\c{c}}{\~a}o chuvosa. J{\'a} o
evento de 2010 foi determinado por mudan{\c{c}}as no
comportamento da circula{\c{c}}{\~a}o zonal, durante o
ver{\~a}o, quando o El Niņo atuou, e tamb{\'e}m na
circula{\c{c}}{\~a}o meridional, principalmente devido as
anomalias de TSM no ATN. Sua severidade p{\^o}de ser
atribu{\'{\i}}da {\`a} atua{\c{c}}{\~a}o simult{\^a}nea
destes padr{\~o}es at{\'{\i}}picos, e a persist{\^e}ncia de
intensos movimentos ascendentes no oceano durante a
esta{\c{c}}{\~a}o seca. Dos resultados encontrados {\'e}
poss{\'{\i}}vel concluir portanto, que eventos secos na
Amaz{\^o}nia est{\~a}o diretamente relacionados a
mudan{\c{c}}as nos padr{\~o}es de escoamento em baixos e
m{\'e}dios n{\'{\i}}veis, assim como modifica{\c{c}}{\~o}es
na circula{\c{c}}{\~a}o zonal e meriodional. ABSTRACT: Droughts
are meteorological events capable of causing severe socioeconomic
disturbances, and although their definition may vary according to
the purpose of the studies involved and the climate of the
affected regions, they may be characterized by a water deficit
because of below-expected rainfall. In Amazon there is a largest
tropical rainforest and watershed in the world, making it a biome
of peculiar characteristics. It is known that the El Niņo-Southern
Oscillation and the anomalous heating of the surface of the North
Atlantic Ocean directly impact on the atmospheric conditions of
this region, and projections indicate a possible increase in the
frequency and severity of these episodes, associated to such
phenomena. Although some studies have recently analyzed their
causes and impacts, some aspects of the 1997-98, 2005-06 and 2010
droughts are still not well understood, as the characteristics of
the average circulation during the events. The objective of this
study is therefore to identify how the 1997-1998, 2005 and 2010
events teleconnections affected the atmospheric circulation of the
Amazon region during periods of drought, specifically the Haddley
and Walker circulations. The results showed that anomalous zonal
circulation patterns were determinant for the occurrence of the
dry event of 1997-1998 since there was an inversion of the
position of the ascending branches and subsidence of the Walker
cell. The meridional component also determined the changes in the
rainfall regime, and its anomalies were probably associated with
the weakening of the Al{\'{\i}}sios winds. The dry conditions
that culminated in the 2005 event were determined, for the most
part, by Hadley's meridional circulation anomalies, with an upward
branch moving to the northeast. Precipitation anomalies in the
Amazon basin persisted mainly during the dry season of 2004 and
2005, however intense positive anomalies of vertical movement on
the ATN were observed in the rainy season. The event of 2010 was
determined by changes in the behavior of the zonal circulation,
during the summer, when the El Niņo played, and also in the
meridional circulation, mainly due to the SST anomalies in the
ATN. Its severity could be attributed to the simultaneous
performance of these atypical patterns, and the persistence of
intense upward movements in the ocean during the dry season. From
the results it is possible to conclude that dry events in the
Amazon are directly related to changes in flow patterns at low and
medium levels, as well as changes in zonal and meriodional
circulation.",
committee = "Arav{\'e}quia, Jos{\'e} Antonio (Presidente) and Herdies, Dirceu
Luis (Orientador) and Souza, Diego Oliveira de (Orientador) and
Quadro, Mario Francisco Leal de and M{\"u}ller, Gabriela
Viviana",
englishtitle = "Analysis of atmospheric patterns associated to dry events in the
Amazon basin",
language = "pt",
pages = "136",
ibi = "8JMKD3MGP3W34R/3R6QKJH",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3R6QKJH",
targetfile = "publicacao.pdf",
urlaccessdate = "25 abr. 2024"
}