@PhDThesis{Latinovic:2018:DeEvGl,
author = "Latinovic, Dragan",
title = "Development and evaluation of Global Eta Framework (GEF) model at
medium and seasonal ranges",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2018",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2018-02-28",
keywords = "Global Eta Framework, eta coordinate, cubed-sphere, monsoon onset,
diurnal cycle, global model, Global Eta Framework, coordenada eta,
esfera c{\'u}bica, in{\'{\i}}cio da esta{\c{c}}{\~a}o
chuvosa, ciclo diurno, modelo global.",
abstract = "The objective of this research is to implement the Global Eta
Framework (GEF) model and evaluate its performance in medium and
seasonal range integrations. GEF is a global atmospheric model on
cubed-sphere grid, constructed as a combination of the technique
of quasi-uniform gridding of the sphere and the numerical
structure of the regional Eta model. Six regional models,
interconnected through the cubed-sphere framework are integrated
simultaneously, one on each side of the cube, to provide a global
coverage and to create unique globalized version of the regional
Eta model. Two model setups of the model are developed and
configured, one at 25-km horizontal resolution for seasonal range
runs and another at 8-km horizontal resolution for medium-range
runs. Total of 10 seasonal integrations of approximately 4 months
are performed creating 5 member ensembles for the period
September- November (SON) of 2011 and 2013 with the objective to
evaluate the model skill to simulate the onset of the rainy season
in Western-Central Brazil (WCB). Comparative assessment of daily
means of global model output fields against appropriate reanalysis
and observations for the austral spring indicates high level of
agreement, both in spatial distribution and intensity for most of
the variables. The lowest skill is shown for precipitation which
is overestimated over some tropical oceanic regions and
underestimated over tropical continental regions, including South
America. Other fields, evaluated at different levels include
200-hPa wind from upper-troposphere, 500-hPa geopotential height
from mid-troposphere, 850-hPa temperature and wind representing
lowertroposphere and mean sea level pressure (MSLP) at the
surface. The onset of the rainy season is determined by using
methods based on precipitation and outgoing long-wave radiation
(OLR). Comparison of 5-day averaged values (pentads) of
precipitation and OLR of the ensemble members and the ensemble
mean against observed data shows the ability of GEF to reproduce
the typical pattern of transition from dry to wet season in WCB
almost in the same pentad determined by both methods. However,
most of ensemble members tend to underestimate precipitation and
overestimate OLR. The other set of integrations viii is performed
at 8-km horizontal resolution, for the length of 10 days. The
total of 22 integrations is performed with the lead times of 24 h,
48 h and 72 h to analyze 8 selected cases of extreme rainfall over
the city of Manaus, Amazonas. The model demonstrates the ability
to simulate well the large-scale patterns for the period of up to
7 days. The Equitable Threat Score (ETS) for the time ranges of 36
h and 60 h shows that the model simulates well the areas with
precipitation, while for the higher thresholds, the results are on
the lower limit of referential values. The BIAS score (BIAS) shows
almost perfect score for the lowest rain-no rain threshold, and
decreases rapidly for the other thresholds. The areas with
precipitation over South America are well simulated by the model,
with comparable intensity in extratropical regions and mostly
underestimated values in the tropical regions. The model simulated
rain for Manaus in almost every simulation, with underestimated
values in most of the cases, in addition to showing the low skill
in the simulation of the positions of the precipitation maxima in
Central Amazon. The computational efficiency of GEF and the
results presented in this study show that continuous efforts in
the development of the GEF model can give significant contribution
to the improvement of medium-range and seasonal forecasts at
CPTEC. Improvements mostly related to the parameterization of
convection and radiation, and the ongoing development of
nonhydrostatic version should position GEF as a good candidate for
future unified model of the centre, capable of running across a
range of scales. RESUMO: O objetivo desta pesquisa {\'e}
implementar o modelo Global Eta Framework (GEF) e avaliar seu
desempenho em simula{\c{c}}{\~o}es sazonais e de prazo
m{\'e}dio. O GEF {\'e} um modelo atmosf{\'e}rico global em
grade c{\'u}bica, desenvolvido a partir de uma
combina{\c{c}}{\~a}o da t{\'e}cnica de grades quasi-uniformes e
a estrutura num{\'e}rica do modelo Eta regional. Seis modelos
regionais, interconectados atrav{\'e}s da estrutura da grade
c{\'u}bica, s{\~a}o integrados simultaneamente, um em cada face
do cubo, para fornecer uma cobertura global e criar uma
vers{\~a}o {\'u}nica {"}globalizada{"} do modelo Eta regional.
Duas vers{\~o}es do modelo s{\~a}o desenvolvidas e configuradas,
uma com resolu{\c{c}}{\~a}o horizontal de 25 km para
simula{\c{c}}{\~o}es sazonais e outra com a
resolu{\c{c}}{\~a}o horizontal de 8 km para testes de m{\'e}dio
prazo. Um total de 10 integra{\c{c}}{\~o}es sazonais de
aproximadamente 4 meses s{\~a}o realizadas para o
per{\'{\i}}odo setembronovembro (SON) de 2011 e 2013 com o
objetivo de avaliar a capacidade do modelo para simular o
in{\'{\i}}cio da esta{\c{c}}{\~a}o chuvosa na regi{\~a}o
Centro-Oeste do Brasil (COB). Integra{\c{c}}{\~a}o para cada ano
consiste de um conjunto de 5 membros. A compara{\c{c}}{\~a}o
entre as medias di{\'a}rias dos campos globais simulados e a
rean{\'a}lise ou as observa{\c{c}}{\~o}es para o
per{\'{\i}}odo SON indica boa concord{\^a}ncia, tanto na
distribui{\c{c}}{\~a}o espacial quanto na intensidade para a
maioria das vari{\'a}veis. A simula{\c{c}}{\~a}o de
precipita{\c{c}}{\~a}o mostra desempenho mais baixo devido
{\`a} superestimativa em algumas regi{\~o}es oce{\^a}nicas
tropicais e {\`a} subestimativa em regi{\~o}es continentais
tropicais, incluindo a Am{\'e}rica do Sul. Outras vari{\'a}veis
avaliadas em diferentes n{\'{\i}}veis, incluem o vento de 200
hPa, altura geopotencial de 500 hPa, temperatura e vento de 850
hPa e press{\~a}o do n{\'{\i}}vel m{\'e}dio do mar. O
in{\'{\i}}cio da esta{\c{c}}{\~a}o chuvosa {\'e} determinado
utilizando os m{\'e}todos baseados em precipita{\c{c}}{\~a}o e
radia{\c{c}}{\~a}o da onda longa (ROL). A compara{\c{c}}{\~a}o
de valores m{\'e}dios de 5 dias (pentadas) de
precipita{\c{c}}{\~a}o e ROL dos membros de conjunto e a
m{\'e}dia do conjunto com os dados observados mostra a capacidade
do modelo GEF em reproduzir o padr{\~a}o de transi{\c{c}}{\~a}o
da x esta{\c{c}}{\~a}o seca para esta{\c{c}}{\~a}o chuvosa na
regi{\~a}o COB. No entanto, a maioria dos membros do conjunto
tende a subestimar a precipita{\c{c}}{\~a}o e a superestimar a
ROL. Um outro conjunto de integra{\c{c}}{\~o}es {\'e} produzido
na resolu{\c{c}}{\~a}o horizontal de 8 km, para o prazo de 10
dias. Um total de 22 integra{\c{c}}{\~o}es s{\~a}o realizadas
com o lead time de 24 hs, 48 hs e 72 hs para analisar 8 casos
selecionados de precipita{\c{c}}{\~a}o extrema sobre a cidade de
Manaus, AM. O modelo demonstrou a capacidade de simular bem os
padr{\~o}es de grande escala no per{\'{\i}}odo de at{\'e} 7
dias. O Equitable Threat Score (ETS) para os intervalos de tempo
de 36 hs e 60 hs mostra que o modelo simula bem as {\'a}reas com
precipita{\c{c}}{\~a}o, enquanto que para os limiares mais
altos, os resultados est{\~a}o no limite inferior dos valores
referenciais. O {\'{\i}}ndice BIAS (BIAS) mostra o valor
pr{\'o}ximo a 1 para o menor limiar {"}chuva-sem chuva{"} e
diminui rapidamente para os outros limiares. As {\'a}reas com
precipita{\c{c}}{\~a}o sobre a Am{\'e}rica do Sul s{\~a}o bem
simuladas pelo modelo, com intensidade compar{\'a}vel em
regi{\~o}es extratropicais e valores principalmente subestimados
nas regi{\~o}es tropicais. O modelo simulou chuva para Manaus em
quase todas as integra{\c{c}}{\~o}es, com valores subestimados
na maioria dos casos, mostrando dificuldades na
simula{\c{c}}{\~a}o das posi{\c{c}}{\~o}es dos m{\'a}ximos de
precipita{\c{c}}{\~a}o na Amaz{\^o}nia Central. A
efici{\^e}ncia computacional do GEF e os resultados apresentados
neste estudo confirmam que esfor{\c{c}}os cont{\'{\i}}nuos no
desenvolvimento do modelo podem dar uma contribui{\c{c}}{\~a}o
significativa na melhoria da previs{\~a}o sazonal e de m{\'e}dio
prazo no CPTEC. As melhorias relacionadas principalmente com a
parametriza{\c{c}}{\~a}o de convec{\c{c}}{\~a}o e
radia{\c{c}}{\~a}o, juntamente com o desenvolvimento
cont{\'{\i}}nuo da vers{\~a}o n{\~a}o hidrost{\'a}tica podem
posicionar o GEF como um bom candidato para o futuro modelo
unificado do centro, capaz de atuar em varias escalas.",
committee = "Ferreira, Nelson Jesuz (Presidente) and Chan, Chou Sin
(Orientadora) and Rivero, Silvio Nilo Figueroa and Mesinger, Fedor
and Rancic, Miodrag",
englishtitle = "Desenvolvimento e avalia{\c{c}}{\~a}o do modelo “Global Eta
Framework” (GEF) no prazo m{\'e}dio e sazonal",
language = "en",
pages = "162",
ibi = "8JMKD3MGP3W34R/3QNATU8",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3QNATU8",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}