Fechar
Metadados

@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/rep/8JMKD3MGP3W34R/3QNATU8",
           targetfile = "publicacao.pdf",
        urlaccessdate = "25 nov. 2020"
}


Fechar