@MastersThesis{Costa:2015:EsCaSu,
author = "Costa, Graziela Luzia da",
title = "Estudo das causas da subestimativa da precipita{\c{c}}{\~a}o em
previs{\~a}o de tempo pelo novo modelo atmosf{\'e}rico global do
CPTEC (vers{\~a}o 4.1) sobre a regi{\~a}o da Bacia do Prata",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2015",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2015-05-29",
keywords = "AGCM-CPTEC/INPE, precipita{\c{c}}{\~a}o, bacia do Prata,
precipitation, La Plata basin.",
abstract = "O Modelo de Circula{\c{c}}{\~a}o Geral Atmosf{\'e}rico (MCGA)
do Centro de Previs{\~a}o de Tempo e Estudos Clim{\'a}ticos do
Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE) subestima
sistematicamente a previs{\~a}o de precipita{\c{c}}{\~a}o sobre
a regi{\~a}o da Bacia do Prata, sobretudo na regi{\~a}o sul do
Brasil. Esta diferen{\c{c}}a {\'e} observada em rodadas longas,
por{\'e}m, em integra{\c{c}}{\~o}es curtas j{\'a} {\'e}
poss{\'{\i}}vel notar esta falha, com VI{\'E}S negativo nas
previs{\~o}es de 1 a 5 dias. Neste trabalho, foi proposto
investigar as poss{\'{\i}}veis causas dessa falha na
previs{\~a}o de tempo utilizando-se a nova vers{\~a}o do MCGA
(v.4.1) apresentando cinco hip{\'o}teses, sendo elas: 1) as
falhas em simular a precipita{\c{c}}{\~a}o na regi{\~a}o
s{\~a}o devidas a baixa resolu{\c{c}}{\~a}o do modelo; 2) o
esquema de parametriza{\c{c}}{\~a}o da superf{\'{\i}}cie
n{\~a}o simula adequadamente os processos de troca de umidade
pr{\'o}ximo a superf{\'{\i}}cie, o que pode gerar um deficit na
umidade dispon{\'{\i}}vel na camada limite planet{\'a}ria; 3) o
modelo de microf{\'{\i}}sica de nuvens falha ao simular os
processos de forma{\c{c}}{\~a}o de precipita{\c{c}}{\~a}o; 4)
os padr{\~o}es de circula{\c{c}}{\~a}o da atmosfera na
Am{\'e}rica do Sul, incluindo os Jatos de Baixos N{\'{\i}}veis
(JBN) e suas consequ{\^e}ncias na forma{\c{c}}{\~a}o de chuva
na regi{\~a}o da Bacia do Prata, n{\~a}o est{\~a}o sendo bem
simulados e 5) efeitos n{\~a}o-locais, como a m{\'a}
representa{\c{c}}{\~a}o de sistemas de escala global atuando
sobre o sul do Oceano Pac{\'{\i}}fico ou {\'{\I}}ndico,
favorecendo precipita{\c{c}}{\~a}o em locais equivocados e seca
na regi{\~a}o da Bacia do Prata. Os resultados mostraram que a
vers{\~a}o em alta resolu{\c{c}}{\~a}o do MCGA (T666L64, 20 km
de resolu{\c{c}}{\~a}o horizontal) sem nenhum ajuste nas
parametriza{\c{c}}{\~o}es f{\'{\i}}sicas apresenta muito pouca
melhora na previs{\~a}o de chuva na regi{\~a}o de estudo em
rela{\c{c}}{\~a}o a vers{\~a}o T299L64 (45 km). Da mesma
maneira, os testes com diferentes parametriza{\c{c}}{\~o}es de
microf{\'{\i}}sica e de superf{\'{\i}}cie apresentaram pouca
diferen{\c{c}}a em rela{\c{c}}{\~a}o ao experimento controle.
Os padr{\~o}es de circula{\c{c}}{\~a}o sobre a Am{\'e}rica do
Sul, no geral, est{\~a}o sendo bem representados pelo MCGA,
embora diferen{\c{c}}as na distribui{\c{c}}{\~a}o da umidade
tenha sido observada durante o per{\'{\i}}odo com
ocorr{\^e}ncia de JBN. Os resultados obtidos n{\~a}o foram
conclusivos sobre a causa da subestimativa da
precipita{\c{c}}{\~a}o em estudo, pois em alguns casos o deficit
de chuva sobre a regi{\~a}o do Prata esteve associado ao erro do
modelo em simular o JBN, enquanto em outros n{\~a}o. A
avalia{\c{c}}{\~a}o das previs{\~o}es de bloqueios pelo MCGA
mostrou que, para previs{\~o}es com 24 h de anteced{\^e}ncia, o
modelo apresentou boa destreza, ao contr{\'a}rio das
previs{\~o}es para 120 h, em que o modelo n{\~a}o foi capaz de
simular t{\~a}o bem todos os eventos, bem como sua
localiza{\c{c}}{\~a}o e intensidade. Entretanto, n{\~a}o foi
encontrada rela{\c{c}}{\~a}o entre bloqueios nos oceanos
{\'{\I}}ndico e Pac{\'{\i}}fico Central e Oeste com a chuva
sobre a regi{\~a}o do Prata. Existem evid{\^e}ncias, embora
n{\~a}o conclusivas, de que erros na simula{\c{c}}{\~a}o de
bloqueios ao oeste do Chile (Oceano Pac{\'{\i}}fico leste) podem
gerar erros na precipita{\c{c}}{\~a}o sobre a regi{\~a}o de
estudo. ABSTRACT: The Atmospheric General Circulation Model (AGCM)
from CPTEC/INPE systematicalIy underestimates the prediction of
rainfalI over La Plata Basin, especialIy in southern Brazil. This
difference is observed on long simulations, however in short
integrations it is already possible to notice this failure with
negative BIAS in forecasts for 1-5 days. In this work, it was
proposed to investigate the possible causes of failure in forecast
using the new version of MCGA (v.4.1) featuring five hypotheses,
which are: 1) the failure to simulate the rainfalI in the region
are due to low resolution model; 2) the surface parameterization
scheme does not adequately simulate the moisture exchange
processes near the surface, which can generate a deficit in
moisture available in the planetary boundary layer; 3)
microphysics scheme fails to simulate the cloud precipitation
formation process; 4) atmospheric circulation pat¬terns in South
America, including the low level jets (LLJ) and its consequences
in the rain formation over La Plata Basin region are not well
simulated and 5) this Iailure may be related to non-local effects
such as the misrepresentation of global systems acting on the
South Pacific or Indian Ocean, favoring precipitation in wrong
places and drought in the La Plata Basin. The results showed that
the high resolu¬tion version of the.ACGM (T666L64, 20 km
horizontal resolution) shows very little improvement in the rain
prediction over the T299 version (45 km), simmilar the tests with
different parameterizations of microphysics and surface. The
circulation patterns over South America, in general, are being
well represented by the ACGM. meanwhile differences in
distribuction of humidity have been observed during period with
LLJ occurrence. Results for this item were inconclusive as the
cause of underestimation because in some cases the rain deficit
over la Plata region it was associated with model error in
simulating the LLJ, while in others noto The study of atmospheric
blockings prediction by ACGM showed that for forecasts 24 hours in
advance, the model showed good results, oposite to predictions for
120h, where the model was not able to simulate so well all events
as well as its location and intensity. However, it was not found
relationship between atmospheric blockings in the Indian Ocean and
the Pacific Central and West with rain on the La Plata region.
There is evidence, though not conclusive, that errors in the
atmospheric blocking simulation over west of Chile (eastern
Pacific) can generate errors in precipitation over study area.
ABSTRACT: The Atmospheric General Circulation Model (AGCM) from
CPTEC/INPE systematicalIy underestimates the prediction of
rainfalI over La Plata Basin, especialIy in southern Brazil. This
difference is observed on long simulations, however in short
integrations it is already possible to notice this failure with
negative BIAS in forecasts for 1-5 days. In this work, it was
proposed to investigate the possible causes of failure in forecast
using the new version of MCGA (v.4.1) featuring five hypotheses,
which are: 1) the failure to simulate the rainfalI in the region
are due to low resolution model; 2) the surface parameterization
scheme does not adequately simulate the moisture exchange
processes near the surface, which can generate a deficit in
moisture available in the planetary boundary layer; 3)
microphysics scheme fails to simulate the cloud precipitation
formation process; 4) atmospheric circulation patterns in South
America, including the low level jets (LLJ) and its consequences
in the rain formation over La Plata Basin region are not well
simulated and 5) this Iailure may be related to non-local effects
such as the misrepresentation of global systems acting on the
South Pacific or Indian Ocean, favoring precipitation in wrong
places and drought in the La Plata Basin. The results showed that
the high resolution version of the.ACGM (T666L64, 20 km horizontal
resolution) shows very little improvement in the rain prediction
over the T299 version (45 km), simmilar the tests with different
parameterizations of microphysics and surface. The circulation
patterns over South America, in general, are being well
represented by the ACGM. meanwhile differences in distribuction of
humidity have been observed during period with LLJ occurrence.
Results for this item were inconclusive as the cause of
underestimation because in some cases the rain deficit over la
Plata region it was associated with model error in simulating the
LLJ, while in others noto The study of atmospheric blockings
prediction by ACGM showed that for forecasts 24 hours in advance,
the model showed good results, oposite to predictions for 120h,
where the model was not able to simulate so well all events as
well as its location and intensity. However, it was not found
relationship between atmospheric blockings in the Indian Ocean and
the Pacific Central and West with rain on the La Plata region.
There is evidence, though not conclusive, that errors in the
atmospheric blocking simulation over west of Chile (eastern
Pacific) can generate errors in precipitation over study area.",
committee = "Moscati, Marley Cavalcante de Lima (presidente) and Bonatti,
Jos{\'e} Paulo (orientador) and Rivero, Silvio Nilo Figueroa
(orientador) and Marques, Rosa de F{\'a}tima Cruz",
copyholder = "SID/SCD",
englishtitle = "Causes of underestimation of precipitation in forecasting by the
new global atmospheric circulation model (AGCM-CPTEC/INPE V. 4.1)
over La Plata Basin",
language = "pt",
pages = "83",
ibi = "8JMKD3MGP3W34P/3JTUQQS",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3JTUQQS",
targetfile = "publicacao.pdf",
urlaccessdate = "19 abr. 2024"
}