Geopotential
Mostrando 13-24 de 28 artigos, teses e dissertações.
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13. Quasi-stationary waves in the southern hemisphere: observations and climate simulations over South America / Ondas quase-estacionárias no hemisférico sul: observações e simulações climáticas sobre a América do Sul
Characteristics of the quasi-stationary waves in the Southern Hemisphere with emphasis on their behavior over South America are discussed. In the first part, an observational study is performed using the NCEP/NCAR reanalysis data. The nature of seasonal and inter anual variabilities is analyzed. A comparison between the of the quasi-stationary wave s amplitu
Publicado em: 2004
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14. Utilização de redes neurais na determinação de modelos geoidais / Using artificial neural network to obtain geoid models.
Applying data from EGM96 geopotential model, gravimetric, GPS and geometric leveling data and using spherical harmonics and FFT as techniques of geoidal determination, this thesis has the goal to find a fast alternative tool to define a geoidal undulation model considering precision and a small effort to estimate important parameters to obtain the mentioned
Publicado em: 2003
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15. Frontogenesis over south america and precursors for the cold surges in the state of São Paulo / Frontogênese na América do Sul e precursores de friagem no estado de São Paulo
Intense cold air incursions in São Paulo (freezes) occur on the average once a year during the months of April through September and 80% during the months of May through August. The central part of the South American continent is frontogenetic due to the horizontal deformation field in the lower troposphere on winter. Composites of the frontogenesis functio
Publicado em: 2003
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16. Determination of geoid model to State of São Paulo. / Obtenção de um modelo geoidal para o Estado de São Paulo.
O sistema GPS tem sido largamente usado para posicionamento. Vislumbra-se o potencial uso deste sistema para determinação de altitudes ortométricas, substituindo o oneroso e demorado processo de nivelamento geométrico. Para isso, um modelo geoidal com precisão absoluta submétrica e precisão relativa da ordem de 2 ppm é necessário. Este modelo pode s
Publicado em: 2002
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17. Assimilacao de informacao de radiâncias em modelos de previsao númerica do tempo utilizando um sistema de análise objetiva estatístico em espaco-físico / Assimilation of radiances information in numerical weather prediction model using a physical space statistical analysis system
The use of radiances in data assimilations systems can be of two forms: direct assimiliation, or they may be pre-processed to retrieve geophysical parameters, like temperature or humidity for subsequent assimilation. The second process involved the invertion of a radiative transfer equation that is ill-posed, and therefore requires the use of prior informati
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 200010
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18. Tests on the geopotential model EGM96 in São Paulo State Region
Anais da Academia Brasileira de Ciências. Publicado em: 2000-06
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19. Assimilacao de informacao de radiâncias em modelos de previsao númerica do tempo utilizando um sistema de análise objetiva estatístico em espaco-físico / Assimilation of radiances information in numerical weather prediction model using a physical space statistical analysis system
The use of radiances in data assimilations systems can be of two forms: direct assimiliation, or they may be pre-processed to retrieve geophysical parameters, like temperature or humidity for subsequent assimilation. The second process involved the invertion of a radiative transfer equation that is ill-posed, and therefore requires the use of prior informati
Publicado em: 2000
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20. Performance of the CPTEC/COLA global model during SACZ episodes using kuo and relaxed arakawa-schubert deep convection schemes / Desempenho do modelo global CPTEC/COLA durante episódios de ZCAS, utilizando os esquemas de convecção profunda tipo kuo e arakawa-schubert relaxada
One of the most important meteorological phenomena during summer in South America is the South Atlantic Convergence Zone (SACZ). Several studies have been accomplished in order to understand the atmospheric dynamics involved in its formation. In this work, the performance of the Center for Weather Forecast and Climate Studies (CPTEC) global model is evaluate
Publicado em: 1999
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21. Synoptic-dinamic study of cyclogenesis using potential vorticity / Estudo sinotico-dinamico de ciclogenese usando vorticidade potencial
A case study of cyclogenesis that occured on 9-10 of July, 1996 over Uruguay was performed. The data utilized consists on the daily temperature, geopotential, pressure at mean sea level, vertical velocity and wind fields, at 17 isobaric levels, from NCEP. The study was based on isobaric and isentropic analysis of those meteorological parameters, and also on
Publicado em: 1999
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22. Variabilidade interanual de campos atmosféricos totais e zonalmente assimétricos / Interannual variability of total and zonally asymmetric atmospheric fields
Interannual variability of total and zonally asymmetric atmospheric fields is studied through analyses of variances and Empirical Orthogonal Function (EOF) patterns as well as using correlation maps between principal component time series and filtered anomalous time series of some variables for DJF and JJA periods. The period of study spans from 1979 to 1995
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/03/1998
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23. Interannual variability of total and zonally asymmetric atmospheric fields / Variabilidade interanual de campos atmosféricos totais e zonalmente assimétricos
Interannual variability of total and zonally asymmetric atmospheric fields is studied through analyses of variances and Empirical Orthogonal Function (EOF) patterns as well as using correlation maps between principal component time series and filtered anomalous time series of some variables for DJF and JJA periods. The period of study spans from 1979 to 1995
Publicado em: 1998
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24. Simulacao de geadas no Sul do Brasil com um modelo de area limitada / Frost simulation in the Southern Brazil whit a limited area model
In this work, the limited area model developed by researchers of the Numerical Prediction Division of the Japan Meteorological Agency was tested in simulating frosts in the Southern Brazil. Simulations have been done with 24 and 48 hours preceding the first day of frost, for 14 cases of severe frosts occurred at decade of 801 The model performance was evalua
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 199711