@PhDThesis{Rocha:2001:BaUmIn,
author = "Rocha, Edson Jos{\'e} Paulino",
title = "Balan{\c{c}}o de umidade e influ{\^e}ncia de
condi{\c{c}}{\~o}es de contorno superficiais sobre a
precipita{\c{c}}{\~a}o da Amaz{\^o}nia",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2001",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2001-03-26",
keywords = "balan{\c{c}}o de {\'a}gua, precipita{\c{c}}{\~a}o,
Amaz{\^o}nia (regi{\~a}o), modelo do CPTEC,
condi{\c{c}}{\~o}es de contorno, previs{\~a}o clim{\'a}tica.",
abstract = "A Amaz{\^o}nia {\'e} uma regi{\~a}o com baixa densidade de rede
de observa{\c{c}}{\~o}es meteorol{\'o}gicas. A
utiliza{\c{c}}{\~a}o de re-an{\'a}lises do ECMWF e do NCEP,
viabilizou a determina{\c{c}}{\~a}o do balan{\c{c}}o de umidade
na Amaz{\^o}nia. As vari{\'a}veis do balan{\c{c}}o de umidade
foram calculadas a partir das re-an{\'a}lises do ECMWF.
Observa-se que os campos de umidade espec{\'{\i}}fica e vento
nos baixos n{\'{\i}}veis atmosf{\'e}ricos (at{\'e} 400 hPa),
s{\~a}o bem representados e, portanto, os campos de {\'a}gua
precipit{\'a}vel e fluxos de umidade integrados na coluna
atmosf{\'e}rica, s{\~a}o pr{\'o}ximos aos observados.
Entretanto, os campos de precipita{\c{c}}{\~a}o e
diverg{\^e}ncia de umidade tendem a seguir os resultados dos
modelos utilizados para obten{\c{c}}{\~a}o das rean{\'a}lises,
onde os centros de m{\'a}ximas precipita{\c{c}}{\~o}es,
associados aos sistemas de grande escala e escala sin{\'o}tica
(ITCZ e ZCAS), s{\~a}o bem acentuados e deslocados mais para o
sul em rela{\c{c}}{\~a}o {\`a} climatologia de
precipita{\c{c}}{\~a}o observada, superestimando a
precipita{\c{c}}{\~a}o no Nordeste brasileiro e subestimando-a
na Amaz{\^o}nia. Tamb{\'e}m no modelo CPTEC/COLA, a
parametriza{\c{c}}{\~a}o da convec{\c{c}}{\~a}o profunda de
Kuo-Anthes, concentra a precipita{\c{c}}{\~a}o nos m{\'a}ximos
de converg{\^e}ncia associados a ZCAS e ITCZ, devido a isso, o
termo de parti{\c{c}}{\~a}o b, foi alterado para que a atmosfera
sempre contivesse 20% da umidade espec{\'{\i}}fica, houve uma
melhor distribui{\c{c}}{\~a}o da precipita{\c{c}}{\~a}o sobre
a Amaz{\^o}nia. Ent{\~a}o, utilizou-se este modelo modificado,
para simular e avaliar a influ{\^e}ncia das condi{\c{c}}{\~o}es
de contorno (TSM pr{\'o}ximo ao litoral equatorial da
Am{\'e}rica do Sul, no Pacifico e Atl{\^a}ntico e tipo de
vegeta{\c{c}}{\~a}o) e efeito dos Andes sobre a
precipita{\c{c}}{\~a}o da Amaz{\^o}nia. Observou-se que o papel
da floresta sobre o regime de precipita{\c{c}}{\~a}o {\'e}
muito importante, fazendo com que a precipita{\c{c}}{\~a}o seja
reduzida em at{\'e} 14%, quando a floresta {\'e}
substitu{\'{\i}}da drasticamente por caatinga, por{\'e}m os
m{\'a}ximos de noroeste da Amaz{\^o}nia e nordeste (costa do
Amap{\'a} e Par{\'a}) s{\~a}o mantidos, com menor intensidade
e, o m{\'{\i}}nimo entre estes dois m{\'a}ximos, {\'e}
ampliado afetando mais o centro e nordeste da Regi{\~a}o. As
anomalias de TSM que afetam mais intensamente a
precipita{\c{c}}{\~a}o na Amaz{\^o}nia, s{\~a}o {\`a}s
observadas sobre o Atl{\^a}ntico equatorial na costa nordeste,
observa-se a intensifica{\c{c}}{\~a}o ou
desintensifica{\c{c}}{\~a}o do m{\'a}ximo de
precipita{\c{c}}{\~a}o observado neste litoral, caso a anomalia
seja positiva ou negativa, respectivamente. As
simula{\c{c}}{\~o}es feitas com o modelo modificado considerando
ou n{\~a}o os Andes, mostram que este n{\~a}o tem um papel
fundamental sobre o posicionamento dos m{\'a}ximos de
precipita{\c{c}}{\~a}o da Regi{\~a}o Amaz{\^o}nica, mais
{\'e} importante para a intensifica{\c{c}}{\~a}o do m{\'a}ximo
de precipita{\c{c}}{\~a}o ao longo do eixo noroeste-sudeste,
sendo mais intensa que o normal na extremidade sudeste, {\'a}rea
sobre influ{\^e}ncia da ZCAS. Entretanto, n{\~a}o foram
observados deslocamentos significativos dos grandes sistemas
convectivos (ZCAS e ITCZ), que afetam a Am{\'e}rica do Sul.
ABSTRACT: The Amazon is a region with a small number of
meteorological observation stations. The utilization of the ECMWF
and NCEP re-analyses made if possible to determine the humidity
balance in Amazon. The humidity balance variables were calculated
from the ECMWF re-analyses. The fields of specific humidity and
wind at low atmospheric levels (up to 400 hPa) are well
represented by the ECMWF re-analyses and then, the fields of
precipitable water and humidity fluxes integrated in the
atmospheric column, are similar to the observed. Nevertheless, the
fields of precipitation and humidity divergence tend to follow the
results of the models employed to obtain the re-analyses, where
the centers of maximum precipitations, associated with the systems
of large and synoptic scales (ITCZ and ZCAS), are reasonably
strong and shifted to the South with respect to the climatology of
observed precipitation, overestimating the precipitation in the
Northeast of Brazil and underestimating this in the Amazon. The
deep convective parametrization of Kuo-Anthes, concentrates the
precipitation at the maximum of the convergence associated with
ZCAS and ITCZ. When the partition term b, was modified in order to
keep the atmosphere always with 20% of the specific humidity,
there was an improved distribution of precipitation over the
Amazon. This modified model was em ployed to simulate and assess
the influence of boundary conditions (SST near the equatorial
coast of South America (Atlantic and Pacific) and the type of
vegetation) and the effects of the Andes over the Amazonian
precipitation. There was observed that the role of the forest in
the precipitation regime is very important, producing a 14%
precipitation reduction when the forest is substituted for
caatinga. Nevertheless, the Northeast and Northwest (Amap{\'a}
and Par{\'a} coasts) maximum are kept with smaller intensity and,
the minimum between the two maximum is amplified affecting more
the Center and Northeast of the Amazon. The SST anomalies that
affect more strongly the Amazon precipitation are the observed
over the Equatorial Atlantic at the Northeast coast. The
intensification or the attenuation of the precipitation maximum of
this coast, in case the anomaly is positive or negative,
respectively, are observed. The simulations performed with the
modified model considering or not the Andes, show that they does
not play a fundamental role in the location of the precipitation
maximum in the Amazon region. However, the Andes are important to
the intensification of the precipitation maximum along the
Northeast-Southeast axis. The precipitation is more intense than
the normal at the Southeast extremity, area under the influence of
ZCAS. However, significant motions of large convective systems
(ZCAS and ITCZ) that affect the South American region, were not
observed.",
committee = "Franchito, S{\'e}rgio Henrique (presidente) and Nobre, Carlos
Afonso (orientador) and Marengo, Jos{\'e} Ant{\^o}nio and
Bonatti, Jos{\'e} Paulo and Ambrizzi, T{\'e}rcio and Rocha,
Humberto Ribeiro da",
copyholder = "SID/SCD",
englishtitle = "Humidity balance and the influence of surface boundary conditions
in the amazonian precipitation.",
language = "pt",
pages = "210",
ibi = "6qtX3pFwXQZ3P8SECKy/ARzry",
url = "http://urlib.net/ibi/6qtX3pFwXQZ3P8SECKy/ARzry",
targetfile = "paginadeacesso.html",
urlaccessdate = "01 maio 2024"
}