@MastersThesis{Gurjão:2017:InCoEl,
author = "Gurj{\~a}o, Carlos Diego de Sousa",
title = "Influ{\^e}ncia conjunta do El Niņo-oscila{\c{c}}{\~a}o sul e
dipolo da Ant{\'a}rtica no gelo marinho dos mares de
Bellingshausen-Amundsen e no mar de Weddell",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-08-04",
keywords = "dipolo da Ant{\'a}rtica. El Niņo-oscila{\c{c}}{\~a}o sul. gelo
marinho. teleconex{\~o}es. Antarctic dipole. ENSO. sea ice.
teleconnections.",
abstract = "O Dipolo da Ant{\'a}rtica (DPA) {\'e} um modo de variabilidade
clim{\'a}tica observado em in{\'u}meras vari{\'a}veis
atmosf{\'e}ricas entre os setores do Atl{\^a}ntico e
Pac{\'{\i}}fico do Oceano Austral. O entendimento do DPA tem
ajudado na compreens{\~a}o dos mecanismos de teleconex{\~o}es
entre o Pac{\'{\i}}fico Equatorial Central e os diferentes
setores do Oceano Austral. Existem v{\'a}rios estudos na
literatura que sugerem algum tipo de teleconex{\~a}o entre os
campos de Gelo Marinho (GM) e o clima global. Com base nesta
hip{\'o}tese, este trabalho pretende analisar se o padr{\~a}o
DPA se manifesta no campo de anomalias sazonais de
Concentra{\c{c}}{\~a}o de Gelo Marinho (CGM) e de vari{\'a}veis
atmosf{\'e}ricas de duas bases de dados de rean{\'a}lises atuais
durante eventos extremos do El Niņo Oscila{\c{c}}{\~a}o Sul
(ENOS). A segunda etapa visa avaliar os principais modos de
variabilidade sazonal do campo de CGM e dos campos
atmosf{\'e}ricos adjacentes, isto {\'e}, Press{\~a}o ao
N{\'{\i}}vel M{\'e}dio do Mar (PNMM) e Temperatura do Ar em
Superf{\'{\i}}cie (TAS). O estudo compreende o per{\'{\i}}odo
entre os anos de 1979 e 2014. A liga{\c{c}}{\~a}o entre as
vari{\'a}veis atmosf{\'e}ricas e GM durante o evento ENOS
decorre em uma persist{\^e}ncia de anomalias de GM configurando
um padr{\~a}o DPA confinado entre os setores do Atl{\^a}ntico e
Pac{\'{\i}}fico do Oceano Austral. Em todas as
composi{\c{c}}{\~o}es verificou-se que o padr{\~a}o DPA {\'e}
bem mais definido nos compostos da CGM, no inverno e na primavera.
A influ{\^e}ncia do DPA na variabilidade do GM, assim como na
atmosfera, n{\~a}o foi detectada no ver{\~a}o austral. Outro
ponto de discuss{\~a}o {\'e} a natureza do deslocamento dos
centros de anomalias positivas e negativas da PNMM, durante
eventos de El Niņo. Verificou-se que a localiza{\c{c}}{\~a}o dos
centros de anomalias n{\~a}o coincidiam com as regi{\~o}es do
Atl{\^a}ntico e Pac{\'{\i}}fico do Oceano Austral; um centro de
anomalia positiva centrado na Passagem de Drake {\'e} um exemplo.
Atrav{\'e}s dos campos de anomalias de Altura do Geopotencial
(AGP), verificou-se que os padr{\~o}es cicl{\^o}nicos e
anticicl{\^o}nicos que est{\~a}o confinados entre os setores do
Oceano Austral mantiveramse com a mesma estrutura vertical em toda
a sua profundidade, indicando que o sinal atmosf{\'e}rico {\'e}
basicamente barotr{\'o}pico. A an{\'a}lise das
Fun{\c{c}}{\~o}es Ortogonais Emp{\'{\i}}ricas (FOEs) mostra
que os primeiros modos de variabilidade da CGM, do ver{\~a}o
(DJF) e outono (MAM), no Oceano Austral, apresentam
frequ{\^e}ncia interanual. No entanto, os principais modos do
gelo marinho no inverno (JJA) e primavera (SON) apresentam o
padr{\~a}o DPA e est{\~a}o associados {\`a} influ{\^e}ncia do
ENOS. Os primeiros modos das FOEs associados {\`a} PNMM, em todas
as esta{\c{c}}{\~o}es revelam caracter{\'{\i}}sticas da
Oscila{\c{c}}{\~a}o Ant{\'a}rtica (OA). No geral, este trabalho
cumpriu o objetivo de verificar as respostas da influ{\^e}ncia do
ENOS {\`a}s anomalias do campo atmosf{\'e}rico e impactos
associados no gelo marinho, em escala interanual. ABSTRACT: The
Antarctic Dipole (ADP) is a mode of climatic variability observed
in several atmospheric variables between the Atlantic and Pacific
sectors of the Southern Ocean. The understanding of ADP has helped
in understanding the teleconnection mechanisms between the Central
Equatorial Pacific and the different sectors of the Southern
Ocean. There are several studies in the literature that suggest
some kind of teleconnection between the Sea Ice (SI) fields and
the global climate. Based on this hypothesis, this work intends to
analyze if the ADP pattern is manifested in the field of seasonal
anomalies of Sea Ice Concentration (SIC) and atmospheric variables
of two current reanalysis databases during extreme events of the
El Niņo Southern Oscillation (ENSO). The second stage aims to
evaluate the leading seasonal modes variability of the SIC field
and the adjacent atmospheric fields, i.e., Sea Level Pressure
(SLP) and Surface Air Temperature (SAT). The study comprises the
period between 1979 and 2014.The link between the atmospheric
variables and SI during the ENOS event result in a persistence of
SI anomalies by configuring a confined ADP pattern between the
Atlantic and Pacific sectors of the Southern Ocean. In all
compositions it has been found that the ADP standard is much more
defined in SIC compounds in winter and spring. The influence of
ADP on SI variability, as well as on the atmosphere, was not
detected in the austral summer. Another point of discussion is the
nature of the displacement of the centers of positive and negative
anomalies of the SLP, during El Niņo events. It was found that the
location of the centers of anomalies did not coincide with the
Atlantic and Pacific regions of the Southern Ocean; a center of
positive anomaly centered on the Drake Pass is an example. Through
the Geopotential Height (HGT) anomaly fields it was verified that
the cyclonic and anticyclonic patterns that are confined between
the Southern Ocean sectors remained the same vertical structure
throughout their depth, indicating that the atmospheric signal is
basically barotropic. The analysis of the Empirical Orthogonal
Functions (EOF) shows that the first modes of variability of SIC,
summer (DJF) and autumn (MAM), in the Southern Ocean, present a
yearon- year frequency. However, the leading modes of winter sea
ice (JJA) and spring (SON) show the ADP pattern and are associated
with the influence of ENSO. The first modes of EOF associated to
the SLP, in all the stations reveal characteristics of the
Antarctic Oscillation (AAO). In general, this work fulfilled the
objective of verifying the responses of the ENSO influence to the
atmospheric field anomalies and associated impacts on sea ice, in
inter-annual scale.",
committee = "Coelho, Caio Augusto dos Santos (presidente) and Pezzi, Luciano
Ponzi (orientador) and Gherardi, Douglas Francisco Marcolino and
Justino, Fl{\'a}vio Barbosa",
englishtitle = "Joint influence of El Niņo-southern oscillation and Antarctic
dipole on the Bellingshausen-Amundsen seas sea ice and the Weddell
sea",
language = "pt",
pages = "135",
ibi = "8JMKD3MGP3W34P/3PGUL5B",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3PGUL5B",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}