Cold Fronts
Mostrando 13-24 de 25 artigos, teses e dissertações.
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13. Climatologia e comportamento dos sistemas frontais sobre a América do Sul / Climatology and behaviour of frontal systems in south america
A climatology from 1980 to 2002 of frontal systems that reach Brazil and the main atmospheric patterns related to their displacement over the continent are analysed in this study. A reduction of frontal systems was observed in low latitudes and in summer. During the winter, more cold fronts can reach interior areas of Brazil. There is not a significant seaso
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/04/2005
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14. Study of generation and propagation of the atmospheric gravity waves / Estudos de geração e propagação de ondas de gravidade atmosféricas
In this study the generation and propagation of the atmospheric gravity waves were investigated. The gravity waves in the mesopause region were observed by airglow all sky imaging technique at Cachoeira Paulista (23°S, 45°W), near tropic of Capricorn, and at São João do Cariri (7°S, 36°W), in the equatorial region. A reverse ray tracing method was test
Publicado em: 2004
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15. Estudos de geração e propagação de ondas de gravidade atmosféricas / Study of generation and propagation of the atmospheric gravity waves
O principal objetivo deste trabalho de tese foi à investigação das fontes de geração das ondas de gravidade e o estudo da sua propagação na atmosfera. As ondas de gravidade na região mesosférica foram observadas pelo imageador de aeroluminescência noturna no observatório de Cachoeira Paulista (23°S, 45°O) próximo ao Trópico de Capricórnio, e
Publicado em: 2004
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16. 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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17. Padrões de abundância, riqueza e diversidade de moluscos bivalves na plataforma continental ao largo de Ubatuba, São Paulo, Brasil: uma comparação metodológica
The diversity and richness patterns of bivalve molluscs were studied on the continental shelf of Ubatuba (23º38'S, 45º14'W and 23º25'S, 44º51'W) between 15-120 metres depth. The samples were taken with a rectangular dredge and a beam trawl. The results showed higher values of richness, diversity and evenness for inner shelf (from coast to nearly 50 m dep
Revista Brasileira de Zoologia. Publicado em: 2003-12
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18. Variabilidade interdiurna da convecção na América do Sul: a propagação meridional da convecção / Day-to-day convective variability over south America: the meridional propagation of convection.
A climatology for the meridional propagation of convection (MPC) over South America (SA) for the 1983-93 years is built by using cloud and atmospheric circulation composites. Results reveal three important types of MPC over SA. Type 1 focuses the frequent penetrations of cold fronts that organize tropical convection and move with it towards equator. Type 1 i
Publicado em: 2003
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19. 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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20. Processamento de imagens AVHRR/NOAA visando o monitoramento de estiagem
A great part of the Brazilian territory is vulnerable to the occurrence of frequent intense dry periods since there is a difference between the precipitation and the annual potential evaporation during the year. Some methods have been proposed to assess and monitor the occurrence of a drought, such as that ones based on agroclimatic indexes calculated with g
Publicado em: 2003
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21. Interações trópicos-extratrópicos na escala de tempo intrassazonal durante o verão astral e seus efeitos na América do Sul / Tropical extratropical intraseasonal interactions during austraul summer and effects in south
In this study the interaction among the tropical convection in Indonesian region, the extratropical flow and the tropical convection in the South Atlantic Convergence Zone (SACZ) was analysed regarding the intraseasonal variability. The analyses were performed applying statistical techniques to the daily NCEP/NCAR reanalysis data set and to daily OLR obtaine
Publicado em: 2002
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22. Previsores sinótico-meteorológicos para a dispersão de poluentes na região da grande São Paulo / Synoptic-meteorological predictors for the dispersion of air pollutants in the greater Sao Paulo region
Extreme air pollution levels in the "Greater São Paulo" region were related to synoptic scale systems during the 1979-1982 period. Low levels of air pollution are associated, at the surface, with cold fronts over or to the north of São Paulo city, and with cold anticyclones centered to the south. Upper air winds at 250mb were strong (>25m/s) and in some ca
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/12/1984
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23. Previsores sinótico-meteorológicos para a dispersão de poluentes na região da grande São Paulo / Synoptic-meteorological predictors for the dispersion of air pollutants in the greater Sao Paulo region
Extreme air pollution levels in the "Greater São Paulo" region were related to synoptic scale systems during the 1979-1982 period. Low levels of air pollution are associated, at the surface, with cold fronts over or to the north of São Paulo city, and with cold anticyclones centered to the south. Upper air winds at 250mb were strong (> 25m/s) and in som
Publicado em: 1984
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24. Um estudo sobre interações entre sistemas de circulação de escala sinótica e circulações locais / x
Influences of large scale systems on two types of local circulation, land-sea breeze and mountain-valley wind, are investigated. Convection associated .with the sea breeze is verified by observing the formation of a line of cumulonimbi along the north-northeast coast of South America after 1800 TMG in satellite imagery. Climatological analysis of the occurre
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/02/1982