@PhDThesis{Melo:2007:SiClHo,
author = "Melo, Maria Luciene Dias de",
title = "Simula{\c{c}}{\~o}es de clima para o holoceno m{\'e}dio usando
o MCGA do CPTEC, com {\^e}nfase sobre a Am{\'e}rica do Sul",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2007",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2007-12-10",
keywords = "mudan{\c{c}}as clim{\'a}ticas, paleoclima, holoceno m{\'e}dio,
MCGA do CPTEC, par{\^a}metros orbitais, climate change,
paleoclimatology, mid-holocene, CPTEC AGCM, orbital parameter.",
abstract = "Este trabalho tem o objetivo de analisar o clima do Holoceno
M{\'e}dio (HM) para a Am{\'e}rica do Sul (AS), a partir da
sinergia entre a for{\c{c}}ante dos par{\^a}metros orbitais e
concentra{\c{c}}{\~a}o de CO2, utilizando o modelo de
circula{\c{c}}{\~a}o geral atmosf{\'e}rica (MCGA) do Centro de
Previs{\~a}o de Tempo e Estudos Clim{\'a}ticos (CPTEC) com
resolu{\c{c}}{\~a}o T062 e 28 n{\'{\i}}veis na vertical
(T062L28). Realizaram-se simula{\c{c}}{\~o}es clim{\'a}ticas a
partir da modifica{\c{c}}{\~a}o dos par{\^a}metros orbitais e
concentra{\c{c}}{\~a}o de CO2, para valores t{\'{\i}}picos do
HM, utilizando dois conjuntos de temperatura da
superf{\'{\i}}cie do mar (TSM) [climatol{\'o}gica do AMIP
(HMS1) e gerada pela componente oce{\^a}nica do MCG
oceano-atmosfera acoplado do Institut Pierre Simon Laplace-IPSL
(HMS2)]. Os resultados foram comparados com as
simula{\c{c}}{\~o}es de outros modelos e ind{\'{\i}}cios
paleoclim{\'a}ticos, para compreender como o MCGA do CPTEC
responde {\`a}s mudan{\c{c}}as clim{\'a}ticas e avaliar as
diferen{\c{c}}as do clima da AS no presente e no HM. Os
resultados sugerem clima mais {\'u}mido sobre o nordeste da AS,
devido ao aumento do fluxo de umidade proveniente do oceano
Atl{\^a}ntico trazido pela alta subtropical do Atl{\^a}ntico
Sul, que no HM encontrava-se mais pr{\'o}xima do continente e
ligeiramente mais intensa. Desintensifica{\c{c}}{\~a}o dos
ventos al{\'{\i}}sios no HM acarretou num deslocamento mais ao
norte da Zona de Converg{\^e}ncia Intertropical (ZCIT) e reduziu
o fluxo de umidade do Atl{\^a}ntico tropical para a regi{\~a}o
Amaz{\^o}nica, deixando-a mais seca no HM. Essa
redu{\c{c}}{\~a}o da precipita{\c{c}}{\~a}o tem um impacto
significativo no transporte da umidade da bacia Amaz{\^o}nica
{\`a} Bacia do Prata, e consequentemente sobre a
forma{\c{c}}{\~a}o da Zona de Converg{\^e}ncia do
Atl{\^a}ntico Sul (ZCAS), levando a uma redu{\c{c}}{\~a}o da
precipita{\c{c}}{\~a}o na posi{\c{c}}{\~a}o atual da ZCAS, e
esta foi simulada ligeiramente mais fraca durante o HMS1 e sua
exist{\^e}ncia n{\~a}o foi evidenciada no experimento com as TSM
do IPSL (HMS2). Na temperatura, verificou-se sinal de resfriamento
durante todo ano no HM, sobre a AS, exceto no oeste da regi{\~a}o
Amaz{\^o}nica, que sugere um sinal de ligeiro aquecimento.
Verificou-se intensifica{\c{c}}{\~a}o do fluxo de umidade em 850
hPa, sobre continente, durante o HM, consequ{\^e}ncia da
intensifica{\c{c}}{\~a}o e proximidade do continente da Alta
Subtropical do Atl{\^a}ntico Sul (ASAS). Este padr{\~a}o durante
o ver{\~a}o no HM {\'e} similar ao observado no outono e inverno
no clima presente. Tamb{\'e}m verificou-se a
intensifica{\c{c}}{\~a}o do escoamento a leste dos Andes ao sul
de 20šS, que sugere uma poss{\'{\i}}vel influ{\^e}ncia na
intensidade da circula{\c{c}}{\~a}o do jato de baixos
n{\'{\i}}veis nos regimes clim{\'a}ticos do centro oeste, sul e
sudeste do Brasil. ABSTRACT: Climate variations and change are
analyzed during the Mid-Holocene (MH) for South America (SA),
using the atmospheric general circulation model (AGCM) from the
Center for Weather Forecasts and Climate Studies (CPTEC) with a
T062L28 resolution. Simulations were made by modifying the orbital
parameters and CO2 concentration, using typical MH values used by
other studies on MH simulations, and with sea surface temperature
(SST) data from two different groups [AMIP climatologic (HMS1) and
that generated by the ocean component of the coupled
ocean-atmosphere from the Institute Pierre Simon Laplace-IPSL
(HMS2)]. The results were compared with simulations made by
previous MH climate simulations from the Paleoclimate Modeling
Intercomparison Project (PMIP) I and II and paleoclimate
indicators, to understand how much the CPTEC AGCM is able to
simulate changes in the SA climate during the MH. A wetter
behavior was detected over Northeastern SA during almost all year
long, excepting from autumn where a northward displacement of the
Intertropical Convergence Zone (ITCZ) is verified, associated with
a weakening of the northeast trade winds and the moisture flow
from Tropical Atlantic into the Amazon region. The Amazon region
was found drier except in autumn and spring in the MH. The
reduction of the precipitation has an important impact in the
moisture transport from the Amazon basin to Parana-Plata basin,
and consequently over the South Atlantic Convergence Zone (SACZ)
formation, leading to a reduction of the precipitation in the SACZ
current position. The SCAZ is slightly weaker during HMS1 and its
existence was not detected in the experiment with IPSL TSM (HMS2).
In the temperature, a signal of cooling during all over the year
in the MH was verified, over SA, except in the west of the Amazon
region that suggests evidences for a weak warming. Moisture flow
intensification in the 850 hPa level was verified over the
continent east of the Andes and South of 20 S during the MH, as
consequence of the intensification and proximity of the South
Atlantic Subtropical High (SASH) to the continent. These patterns,
during summer in the MH, are similar to those observed in autumn
and winter in the current climate. Weakening of the moisture flow
from the tropical Atlantic north of 20šS to the East of the Andes
was also verified.",
committee = "Oyama, Marcos Daisuke (presidente) and Orsini, Jos{\'e} Antonio
Marengo (orientador) and Reyes Fernandez, Julio Pablo and Nobre,
Carlos Afonso and Pessenda, Luiz Carlos Ruiz and Dias, Pedro Leite
da Silva",
copyholder = "SID/SCD",
englishtitle = "Climate simulations of the mid-holocene as produced by the CPTEC
atmospheric general circulation model in the South America",
language = "pt",
pages = "201",
ibi = "6qtX3pFwXQZGivnK2Y/SuJ6y",
url = "http://urlib.net/ibi/6qtX3pFwXQZGivnK2Y/SuJ6y",
urlaccessdate = "09 maio 2024"
}