Numerical Weather Forecasting
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Comparing an Ensemble Kalman Filter to a 4DVAR Data Assimilation System in Chaotic Dynamics
ABSTRACT: In this paper, the Ensemble Kalman Filter is compared with a 4DVAR Data Assimilation System in chaotic dynamics. The Lorenz model is chosen for its simplicity in structure and the dynamic similarities with primitive equations models, such as modern numerical weather forecasting. It was examined if the Ensemble Kalman Filter and 4DVAR are effective
J. Aerosp. Technol. Manag.. Publicado em: 2017-12
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2. Verificação da previsão do tempo em São Paulo com o modelo operacional WRF / Review of weather in São Paulo with the WRF Operational Model.
Forecasts of daily maximum and minimum temperatures and rainfall performed by the operational numerical weather prediction WRF (Weather Research Forecasting) model in the São Paulo are evaluated. Initial and boundary conditions provided by the 00UTC Global Forecast System (GFS) Model and WRF run for 72 hours, with two nested grids (with horizontal grid spac
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/11/2012
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3. Assimilação de dados com redes neurais artificiais em modelo de circulação geral da atmosfera / Data assimilation with artificial neural networks in atmospheric general circulation model
Weather forecasting systems require a model for the time evolution and an estimate of the current state of the system. The numerical weather prediction (NWP) incorporates the equations of atmospheric dynamics with physical process and it can predict the future state of the atmosphere. Data assimilation provides such an initial estimate of the atmosphere wher
Publicado em: 2010
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4. Sistema de previsão imediata da precipitação: o hydrotrack / A rainfall nowcasting system: the hydrotrack
The knowledge of convective system evolution is of fundamental importance for understanding weather and climate, particularly in the tropics, and it is essential to improve forecasting of these systems to reduce vulnerability to extreme weather damage. The identification of predictor parameters of the evolution of convective system, based on its previous evo
Publicado em: 2008
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5. Estudo das características das perturbações EOF extratropicais e seu impacto na previsão de tempo de médio prazo por conjunto
- The characteristics of the extratropical EOF perturbations are studied and their impact on the medium range ensemble weather prediction is evaluated, using simulations with the Center for Weather Prediction and Climate Studies Ensemble Weather Prediction System (CPTEC-EPS). The EOF method, originally applied over tropical regions and for horizontal wind an
Publicado em: 2008
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6. Inclusion of the momentum perturbation in the kain-fritsch cumulus parameterization scheme and impacts on a convective rain case / Inclusão da perturbação de momentum no esquema de parametrização de cumulus kain-fritsch e impactos sobre um caso de chuva convectiva
The objective of this work is to insert the vertical transport of momentum through the mass flux in the Kain-Fritsch convective parameterization scheme. The momentum fluxes were inserted in the KF scheme in a similar way to the existing heat fluxes. Experiments were accomplished in the two domains, one experiment with cloud updraft (FM1) and one experiment i
Publicado em: 2007
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7. Implementation of statistical data assimilation system in physical space to the global model of CPTEC / Implementação do sistema estatístico de assimilação de dados em espaço físico para o modelo global do CPTEC
Atmospheric data (such as temperature, moisture, winds), collected by satellites, direct measurements from upper-air instruments and ground observation stations are used in order to estimate the state of the atmosphere as precise as possible. The estimation process, denominated data assimilation consists of observations, and the physical laws, which govern t
Publicado em: 2004
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8. Implementação do sistema estatístico de assimilação de dados em espaço físico para o modelo global do CPTEC / Implementation of statistical data assimilation system in physical space to the global model of CPTEC
Dados atmosféricos (como temperatura, umidade e ventos), coletados por satélites, medidas diretas de instrumentos de ar-superior e estações de observação de superfície são informações usadas para estimar estado da atmosfera de forma mais precisa possível. Este processo de estimação, que utiliza também as leis físicas consistentes dos modelos n
Publicado em: 2004
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9. Previsão e análise sobre as regiões sudeste e sul do Brasil utilizando redes neurais artificiais / Forecast and analysis of rainfall over south and southeastern Brazil using artificial neural network
This study uses an Artificial Neural Network (ANN) technique to establish a non-linear relationship between the large scale atmospheric circulation and local surface rainfall. The method involves the use of statistical downscaling applied to outputs from Eta model. In this sense, prognostic equations were developed for 18 locations using the ANN. This method
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/12/2003
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10. Analyses of the satellite sounding data assimilation process and the impact on weather forecast using a physical-space statistical analysis system. / Análise do procedimento de assimilação de sondagens derivadas de satélites e de seu impacto na previsão de tempo utilizando um sistema estátístico em espaço físico
Many studies on evaluation of the impact of satellite sounding on forecasts, made by different institutions around the World, have shown that this kind of data are very important to improve the quality of weather forecasting in Southern Hemisphere. There are many methods of data assimilation and models of weather forecasting. In this study we used an adaptat
Publicado em: 2003
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11. Forecast and analysis of rainfall over south and southeastern Brazil using artificial neural network / Previsão e análise sobre as regiões sudeste e sul do Brasil utilizando redes neurais artificiais
This study uses an Artificial Neural Network (ANN) technique to establish a non-linear relationship between the large scale atmospheric circulation and local surface rainfall. The method involves the use of statistical downscaling applied to outputs from Eta model. In this sense, prognostic equations were developed for 18 locations using the ANN. This method
Publicado em: 2003
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12. Um estudo de avaliação estatística do modelo global do CPTEC com relação ao número, trajetória e intensidade de ciclones e anticiclones para o Hemisfério Sul / A statistic evaluation study of CPTEC global model with relation of number, tracking and intensity of cyclones and anticyclones.
A evolução dos modelos numéricos de previsão de tempo, em grande parte, é resultado de avaliações que determinam erros sistemáticos no mesmo. Sendo assim, o modelo global de previsão numérica de tempo do Centro de Previsão de Tempo e Estudos Climáticos (CPTEC) foi submetido a uma avaliação de suas previsões, com o objetivo de encontrar erros s
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/09/2001