@MastersThesis{Medeiros:2011:ImUsRa,
author = "Medeiros, Maria das Dores da Silva",
title = "Impacto do uso de radi{\^a}ncia na assimila{\c{c}}{\~a}o de
dados usando 4D-LETKF na regi{\~a}o da Am{\'e}rica do Sul",
school = "Instituto Nacional de Pesquisas Espaciais",
year = "2011",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2010-12-06",
keywords = "assimila{\c{c}}{\~a}o de dados, LETKF, radi{\^a}ncia, dados de
sat{\'e}lites, data assimilation, Local ensemble Transform Kalman
Filter (LETKF), radiance, satellite data.",
abstract = "O presente trabalho avalia o desempenho do novo sistema 4D-LETKF
na assimila{\c{c}}{\~a}o de dados convencionais e dados de
radi{\^a}ncia de sat{\'e}lite. A assimila{\c{c}}{\~a}o {\'e}
feita com 4D-LETKF acoplado ao Modelo Global do CPTEC, na
resolu{\c{c}}{\~a}o T126L28. Os dados de radi{\^a}ncia
assimilados foram obtidos atrav{\'e}s do sensor \textit{Advanced
Microwave Sounding Unit} A (AMSU-A) a bordo do sat{\'e}lite AQUA.
A {\'a}rea de estudo compreende a Am{\'e}rica do Sul e o
per{\'{\i}}odo estudado foi de 1 a 30 de junho de 2008. Foram
realizados dois tipos de experimentos com o sistema
4D-LETKF/MCGA-CPTEC: o primeiro com assimila{\c{c}}{\~a}o
somente de dados convencionais, e o segundo com
assimila{\c{c}}{\~a}o de dados convencionais e dados de
radi{\^a}ncia do sensor AMSU-A. O principal objetivo dos
experimentos {\'e} determinar o impacto da
assimila{\c{c}}{\~a}o com a inclus{\~a}o de radi{\^a}ncia no
sistema 4D-LETKF/MCGA. A partir das an{\'a}lises do 4D-LETKF/MCGA
foram geradas 48 horas de previs{\~o}es usando o modelo
MCGA/CPTEC. A verifica{\c{c}}{\~a}o das an{\'a}lises e
previs{\~o}es {\'e} feita usando as an{\'a}lises de alta
resolu{\c{c}}{\~a}o do NCEP como verdade para o estado da
atmosfera. Adicionalmente, foi feita outra
verifica{\c{c}}{\~a}o, desta vez usando como verdade para o
estado da atmosfera, as radiossondagens coletadas durante o
Experimento Mini-BARCA/LBA. As an{\'a}lises e previs{\~o}es
usando o 4D-LETKF/MCGA-CPTEC s{\~a}o tamb{\'e}m comparadas ao
sistema de assimila{\c{c}}{\~a}o GPSAS, operacional do CPTEC,
cuja resolu{\c{c}}{\~a}o {\'e} T213L42. Os resultados usando o
4D-LETKF/MCGA-CPTEC foram satisfat{\'o}rios quando comparados
{\`a}s an{\'a}lises do NCEP. A assimila{\c{c}}{\~a}o de
observa{\c{c}}{\~o}es de radi{\^a}ncia pelo sistema apresentou
um ganho com redu{\c{c}}{\~a}o dos erros n{\~a}o somente para
as an{\'a}lises de temperatura, mas tamb{\'e}m para as
an{\'a}lises das componentes horizontais do vento, principalmente
a componente zonal. A redu{\c{c}}{\~a}o dos erros tamb{\'e}m
foi verificada para as previs{\~o}es com redu{\c{c}}{\~a}o dos
erros para a temperatura e componente zonal do vento. As
an{\'a}lises do 4D-LETKF/MCGA apresentaram erros menores que as
an{\'a}lises do GPSAS para a vari{\'a}vel vento em todos os
n{\'{\i}}veis avaliados, apesar da menor resolu{\c{c}}{\~a}o
espacial do 4D-LETKF/MCGA em compara{\c{c}}{\~a}o ao GPSAS. Para
a vari{\'a}vel temperatura, os erros do experimento com
assimila{\c{c}}{\~a}o de radi{\^a}ncia foram menores que os
erros do GPSAS em praticamente todos os n{\'{\i}}veis. Com
rela{\c{c}}{\~a}o {\`a} avalia{\c{c}}{\~a}o da temperatura
usando as radiossondagem do Mini-BARCA, tanto as an{\'a}lises
quanto as previs{\~o}es do sistema 4D-LETKF/MCGA apresentaram
concord{\^a}ncia com os dados observados para as
esta{\c{c}}{\~o}es meteorol{\'o}gicas e per{\'{\i}}odo
estudados. ABSTRACT: This study evaluates the performance of a new
data assimilation system using the Local Ensemble Transform Kalman
Filter (LETKF) with the Atmospheric General Circulation Model
(AGCM) of the CPTEC. This new data assimilation system has been
assessed using data from NCEP analysis. Two types of experiments
was performed with the system 4D-LETKF/MCGA-CPTEC: the first with
only conventional data assimilation, and the second with
conventional and data assimilation of radiance data from the
AMSU-A sensor. The main objective of the experiments is to
determine the impact of assimilation with the inclusion of
radiation in the system 4D-LETKF/MCGA. Analysis of 4D-LETKF/MCGA
were generated 48 hours of forecasts using the model AGCM/CPTEC.
The verification of the analysis and forecasts are made using
analysis of high resolution NCEP as true for the state of the
atmosphere. Additionally, another evaluation was made, this time
using as true for the state of the atmosphere, the rawinsonde data
collected during the Experiment Mini-BARCA/LBA. Analyses and
forecasts using 4D-LETKF/MCGA-CPTEC are also compared to the
assimilation system GPSAS, operational CPTEC, whose resolution is
T213L42. The results using the 4D-LETKF/MCGA-CPTEC were
satisfactory when compared to the NCEP analysis. The radiance
assimilation by the system showed a gain to reduce errors not only
for the analysis of temperature, but also for analysis of
horizontal wind components, mainly zonal. The reduction of errors
was also verified the forecasts with error reduction for the
temperature and zonal wind. Analyses of 4D-LETKF/MCGA had errors
smaller than GPSAS analysis for variable wind at all levels
assessed, despite the lower spatial resolution compared to
4D-LETKF/MCGA assimilation system. For the temperature, the errors
of the experiment with assimilation of radiance were smaller than
the errors of the assimilation system in most part of the levels.
Regarding the assessment of the rawinsonde temperature using the
Mini-BARCA, both analysis and forecast system 4D-LETKF/MCGA agreed
with the observed data.",
committee = "Bonatti, Jos{\'e} Paulo (presidente) and Herdies, Dirceu Luis
(orientador) and Arav{\'e}quia, Jos{\'e} Ant{\^o}nio
(orientador) and Souza, Rita Val{\'e}ria Andreoli de",
copyholder = "SID/SCD",
englishtitle = "Impact of the satellite radiance assimilation using 4D-LETKF
system in the region of South America",
language = "pt",
pages = "137",
ibi = "8JMKD3MGP7W/38LHLTB",
url = "http://urlib.net/ibi/8JMKD3MGP7W/38LHLTB",
targetfile = "publicacao.pdf",
urlaccessdate = "02 maio 2024"
}