Atmospheric Waves
Mostrando 1-12 de 35 artigos, teses e dissertações.
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1. Error Analysis of the Numerical Method for Correcting the Propagation of EM waves in the Troposphere
Abstract Electromagnetic (EM) waves do not travel in straight lines in the troposphere due to refraction. This leads to errors in many engineering applications. In order to correct these errors, a numerical solution based on the difference method has been proposed, which can reveal the degree of EM wave bending owing to atmospheric refraction, moreover, it c
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09
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2. Propagação guiada de ondas de VLF: aplicação ao estudo de fenômenos atmosféricos e naturais
Deep amplitude minima are observed in the daily records of Very Low Frequency (VLF, between 3 - 30 kHz) wave amplitudes. Amplitude minima are attributed to modal interference and modal conversion of waves propagating in the Earth - Ionosphere waveguide. The time of amplitude minima is related with the localization of the Terminator line and, therefore, is de
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/02/2012
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3. Numerical simulation of wind waves on the Río de la Plata: evaluation of four global atmospheric databases
Na região do Rio de la Plata, o desempenho das reanálises globais do NCEP/NCAR I, NCEP/DOE II, JRA-25 e ERAInterim implementadas como forçantes atmosféricas do modelo SWAN foram quantitativamente acessados através do viés, erro quadrático médio, coeficiente de determinação e inclinação da reta. Estes índices foram obtidos dos parâmetros de onda
Braz. j. oceanogr.. Publicado em: 2012-12
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4. Potenciais influências de anomalias positivas e negativas na camada de gelo marinho no mar de Ross na circulação atmosférica do Hemisfério Sul / Potential influences on the southern hemisphere atmospheric circulation of negative and positive sea ice extension anomalies in the ross sea
This study have used the CPTEC/INPE AGCM to explore the role of sea ice extent in the Ross Sea as a forcing of the asymmetric atmospheric circulation in the southern hemisphere during the austral winter (July-September), on a seasonal scale. The impacts have been assessed from the standpoint of positive and negative observed anomalies in ice extent in the Ro
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/03/2011
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5. Influências remotas na previsibilidade, estrutura e ciclo de vida da Zona de Convergência do Atlântico Sul / Remote influences on South Atlantic Convergence Zone predictability, structure and life cycle
Neste estudo é feita uma investigação sobre a modulação espacial das anomalias de convecção em episódios de Zona de Convergência do Atlântico Sul (ZCAS) registrados pelos boletins mensais da Climanálise do CPTEC/INPE em 19 verões (verão estendido outubro a março) compreendidos entre o período de 1990 e 2009. Estes eventos são divididos em tr�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2011
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6. Maré lunar observada com radar meteórico em três latitudes no Brasil / Lunar tide observed with meteor radar at three latitudes in Brazil
Using meteor radar data from three Brazilian sites [São João do Cariri (7.4° S ; 36.5° W), Cachoeira Paulista (22.7° S; 45.0° W) and Santa Maria (29.7° S; 53.8° W)], the atmospheric semidiurnal lunar tide in the mesosphere and lower thermosphere was studied from January 2005 to December 2008. Monthly tidal amplitudes and phases were determined using
Publicado em: 2010
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7. Synchronization in intermittent turbulence and spatiotemporal chaos in the solar-terrestrial environment / Sincronização em turbulência intermitente e caos espaço-temporal no ambiente solar-terrestre
In this work we analyze synchronization due to multiscale interactions in observations of intermittent turbulence and numerical simulations of spatiotemporal intermittency in neutral fluids and space plasmas. This study is carried out in two parts. First, we apply two distinct nonlinear techniques, kurtosis and phase coherence index, to measure the degree of
Publicado em: 2010
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8. Synchronization in intermittent turbulence and spatiotemporal chaos in the solar-terrestrial environment / Sincronização em turbulência intermitente e caos espaço-temporal no ambiente solar-terrestre
In this work we analyze synchronization due to multiscale interactions in observations of intermittent turbulence and numerical simulations of spatiotemporal intermittency in neutral fluids and space plasmas. This study is carried out in two parts. First, we apply two distinct nonlinear techniques, kurtosis and phase coherence index, to measure the degree of
Publicado em: 2010
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9. Electric and magnetic field signatures of gravity waves and 2-day planetary waves in the equatorial E-region / Assinaturas nos campos elétricos e magnéticos às ondas de gravidade e ondas planetárias de 2-dias na região E equatorial
Equatorial electrojet (EEJ) observations using VHF radars show backscattered echoes from two types of electron density irregularities explained by the modified two-stream (Type I) and the gradient drift (Type 11) instabilities. From the Type II irregularity velocities obtained by radar data we have inferred the vertical electric fields (E_z). The harmonic an
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/02/2009
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10. Numerical investigation of the three-dimensional secondary instabilities in the time-developing compressible mixing layer
Mixing layers are present in very different types of physical situations such as atmospheric flows, aerodynamics and combustion. It is, therefore, a well researched subject, but there are aspects that require further studies. Here the instability of two-and three-dimensional perturbations in the compressible mixing layer was investigated by numerical simulat
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-06
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11. Assinaturas nos campos elétricos e magnéticos às ondas de gravidade e ondas planetárias de 2-dias na região E equatorial / Electric and magnetic field signatures of gravity waves and 2-day planetary waves in the equatorial E-region
Equatorial electrojet (EEJ) observations using VHF radars show backscattered echoes from two types of electron density irregularities explained by the modified two-stream (Type I) and the gradient drift (Type 11) instabilities. From the Type II irregularity velocities obtained by radar data we have inferred the vertical electric fields (E_z). The harmonic an
Publicado em: 2009
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12. Electric and magnetic field signatures of gravity waves and 2-day planetary waves in the equatorial E-region / Assinaturas nos campos elétricos e magnéticos às ondas de gravidade e ondas planetárias de 2-dias na região E equatorial
Observações do eletrojato equatorial (EEJ) utilizando radares VHF mostram ecos retro-espalhados em dois tipos de irregularidades de densidade eletrônica, explicadas pelas instabilidades de dois-feixes modificada (ecos Tipo I) e deriva de gradiente (ecos Tipo II). Das velocidades das irregularidades Tipo II obtidas de dados de radar, inferimos os campos el
Publicado em: 2009