@MastersThesis{Simões::InVaIn,
author = "Sim{\~o}es, Paloma Angelina",
title = "Influ{\^e}ncia da variabilidade intrasazonal na variabilidade
interanual do sistema de mon{\c{c}}{\~a}o da Am{\'e}rica do
Sul",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2024-02-08",
keywords = "precipita{\c{c}}{\~a}o, ver{\~o}es mais secos, ver{\~o}es mais
chuvosos, escalas, variabilidade intrasazonal, precipitation, more
dry summers, more rainy summers, scales, intraseasonal
variability.",
abstract = "O Sistema de Mon{\c{c}}{\~a}o da Am{\'e}rica do Sul (SMAS)
{\'e} um dos principais sistemas que contribui para a
precipita{\c{c}}{\~a}o, durante os meses de ver{\~a}o austral,
sobre grande parte da regi{\~a}o tropical da Am{\'e}rica do Sul
(AS), al{\'e}m de influenciar a circula{\c{c}}{\~a}o
atmosf{\'e}rica de grande escala sobre a regi{\~a}o. Perante
isso, o principal objetivo deste estudo foi investigar a
contribui{\c{c}}{\~a}o de oscila{\c{c}}{\~o}es dentro da
escala intrasazonal para a ocorr{\^e}ncia de ver{\~o}es mais
secos e mais chuvosos, durante o per{\'{\i}}odo de 1979 a 2022,
e avaliar a diferen{\c{c}}a nessas an{\'a}lises em tr{\^e}s
sub-regi{\~o}es distintas, que s{\~a}o afetadas pelo SMAS, sendo
elas: Sudeste da Bacia Amaz{\^o}nica (SBA), Centro-Oeste (COB) e
Sudeste (SE) do Brasil. Para tais analises, utilizou-se a
t{\'e}cnica de quantis, para classificar os ver{\~o}es, a
transformada de ondeletas, para avaliar a contribui{\c{c}}{\~a}o
da escala sazonal temporalmente, e compostos de dados filtrados,
para avaliar a contribui{\c{c}}{\~a}o destas escalas com
rela{\c{c}}{\~a}o aos padr{\~o}es an{\^o}malos m{\'e}dios. Os
resultados obtidos indicam que existe uma poss{\'{\i}}vel
tend{\^e}ncia de aumento de ver{\~o}es mais secos e
diminui{\c{c}}{\~a}o de ver{\~o}es mais chuvosos nas tr{\^e}s
regi{\~o}es de an{\'a}lise e que os ver{\~o}es mais secos
destas regi{\~o}es possuem uma rela{\c{c}}{\~a}o com anomalias
positivas da temperatura da superf{\'{\i}}cie do mar sobre o
Atl{\^a}ntico Sul Equatorial. Al{\'e}m disso, os ver{\~o}es
mais secos das tr{\^e}s sub-regi{\~o}es s{\~a}o influenciados
por um padr{\~a}o de um poss{\'{\i}}vel bloqueio, ao sul da AS,
o qual est{\'a} relacionado {\`a} escala entre 11-30 dias. A
an{\'a}lise de ondeletas para o SBA mostrou que a alta
frequ{\^e}ncia exerce influ{\^e}ncia na ocorr{\^e}ncia de
anomalias positivas e negativas de precipita{\c{c}}{\~a}o,
indicando uma poss{\'{\i}}vel atua{\c{c}}{\~a}o de ondas
equatoriais sobre a regi{\~a}o. J{\'a} sobre o COB e SE,
notou-se na maioria dos casos aumento (diminui{\c{c}}{\~a}o) de
precipita{\c{c}}{\~a}o associado ao aumento
(diminui{\c{c}}{\~a}o) de energia nesta escala, sugerindo uma
maior influ{\^e}ncia de sistemas transientes. Com
rela{\c{c}}{\~a}o a escala submensal (11-30 dias) e intrasazonal
(31-90 dias), as mesmas por vezes contribuem para o aumento da
convec{\c{c}}{\~a}o, por vezes para a diminui{\c{c}}{\~a}o,
sugerindo que estas escalas agem de forma a amplificar um sinal
j{\'a} preexistente ao inv{\'e}s de gerar ou inibir a
convec{\c{c}}{\~a}o sobre as regi{\~o}es. Al{\'e}m disso, a
OMJ parece contribuir para a ocorr{\^e}ncia de v{\'a}rios picos
negativos/positivos das anomalias de precipita{\c{c}}{\~a}o. Com
rela{\c{c}}{\~a}o aos padr{\~o}es espaciais, sobre a
regi{\~a}o SBA n{\~a}o se nota nenhuma circula{\c{c}}{\~a}o
associada a ver{\~o}es mais secos e mais chuvosos, ou seja,
padr{\~o}es de teleconex{\~o}es podem estar mais associados
{\`a} din{\^a}mica destes ver{\~o}es, no que tange a escala
sazonal. J{\'a} sobre o COB e SE notamse padr{\~o}es de
circula{\c{c}}{\~o}es anticicl{\^o}nicas/cicl{\^o}nicas em
altos e baixos n{\'{\i}}veis, associadas a escala submensal e
intrasazonal, e que parecem contribuir para a ocorr{\^e}ncia de
ver{\~o}es mais secos e mais chuvosos sobre as regi{\~o}es.
Sobre o SE, os padr{\~o}es, no caso de anos chuvosos, est{\~a}o
associados a modos do tipo PSA e poss{\'{\i}}vel deslocamento da
ZCAS mais ao sul ou pr{\'o}ximo da sua posi{\c{c}}{\~a}o
climatol{\'o}gica. Notam-se padr{\~o}es opostos no HN entre os
anos secos e chuvosos nas regi{\~o}es COB e SE, e que sobre o SE,
estes padr{\~o}es est{\~a}o associados as escalas submensal e
intrasazonal, podendo agir como padr{\~o}es de teleconex{\~o}es
dada a similaridade e sinais opostos. Em s{\'{\i}}ntese, este
trabalho contribui para uma vis{\~a}o abrangente dos padr{\~o}es
intrasazonais que impactam os ver{\~o}es mais secos e mais
chuvosos em diferentes regi{\~o}es do Brasil. ABSTRACT: The South
American Monsoon System (SAMS) is one of the main systems that
contribute to the precipitation, during the southern summer
months, over a large part of the tropical region of South America
(SA), and exerts influence on the large scale atmospheric
circulation over the region. In view of this, the main objective
of this study was to investigate the contribution of oscillations
within the intraseasonal scale to the occurrence of more dry and
more rainy summers, during the period from 1979 to 2022, and to
evaluate the differences in these analyzes in three distinct
sub-regions, which are affected by SMAS, namely: Southeast of the
Amazon Basin (SBA), Central-West (COB) and Southeast (SE) of
Brazil. For such analyses, a quantile technique was used to
classify summers, a wavelet transform to evaluate the contribution
of the seasonal scale and composites of filtered data to evaluate
the contribution of these scales in relation to the average
anomalous patterns. The results obtained indicate that there is a
possible tendency towards an increase in more dry summers and a
decrease in more rainy summers in all three regions. More dry
summers in these regions are related to positive sea surface
temperature anomalies over the South Equatorial Atlantic.
Furthermore, the more dry summers of the three sub-regions are
influenced by a pattern of possible blocking to the south of SA,
related to the scale between 11-30 days. The wavelet analysis for
the SBA showed that high frequency influences the occurrence of
positive and negative precipitation anomalies, indicating a
possible action of equatorial waves over the region. Regarding COB
and SE, an increase (decrease) in precipitation associated with an
increase (decrease) in energy on this scale was noted in most
cases, suggesting a greater influence of transient systems.
Regarding the submonthly (11-30 days) and intraseasonal scales
(31-90 days), they sometimes contribute to an increase in
convection and sometimes to a decrease, suggesting that these
scales act to amplify a pre-existing signal rather than generating
or inhibiting the convection over the regions. Furthermore, the
OMJ appears to contribute to the occurrence of diverses
negative/positive peaks of precipitation anomalies. Regarding
spatial patterns, over the SBA region there is no circulation
associated with more dry and more rainy summers, that is,
teleconnection patterns may be more associated with the dynamics
of these summers, in terms of the seasonal scale. Over the COB and
SE, anticyclonic/cyclonic circulations are noted at high and low
levels, associated with a submonthly and intraseasonal scale, and
which seem to contribute to the occurrence of more dry and more
rainy summers over the regions. In the SE, the patterns are
associated with PSA pattern and possible displacement of the SACZ
further south or close to its climatological position are observed
in rainy years. Opposite patterns are noted in H.N between dry and
rainy years in the COB and SE regions, and over the SE, these
patterns are associated with submonthly and intraseasonal scales,
and can act as teleconnection patterns given the similarity and
opposite signs. In summary, this work contributes to a
comprehensive view of the intraseasonal patterns that impact the
more dry and more rainy summers in different regions of Brazil.",
committee = "Ferreira, Nelson Jesuz (presidente) and Gan, Manoel Alonso
(orientador) and Seluchi, Marcelo Enrique and Calheiros,
S{\^a}mia Regina Garcia",
englishtitle = "Influence of intraseasonal variability on the inter-anual
variability of the South American monsoon system",
language = "pt",
pages = "186",
ibi = "8JMKD3MGP3W34T/4APH8N8",
url = "http://urlib.net/ibi/8JMKD3MGP3W34T/4APH8N8",
targetfile = "publicacao.pdf",
urlaccessdate = "19 maio 2024"
}