Detalhes bibliográficos
| Ano de defesa: |
2018 |
| Autor(a) principal: |
Ricardo da Rosa Paes |
| Orientador(a): |
Esfhan Alam Kherani,
Inez Staciarini Batista |
| Banca de defesa: |
Hisao Takahashi,
Cláudia Maria Nicoli Cândido,
Paulo Roberto Fagundes,
Virgínia Klausner de Oliveira |
| Tipo de documento: |
Tese
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
eng |
| Instituição de defesa: |
Instituto Nacional de Pesquisas Espaciais (INPE)
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação do INPE em Geofísica Espacial
|
| Departamento: |
Não Informado pela instituição
|
| País: |
BR
|
| Link de acesso: |
http://urlib.net/sid.inpe.br/mtc-m21c/2018/07.23.04.02
|
Resumo: |
In this work, we present a numerical simulation study of the acoustic-gravity waves. We developed a simulation model that solves the Navier-Stokes hydrodynamic equations in the atmosphere covering 0-600 km altitudes and 70-0 geographic latitudes in both hemispheres. Using these equations, we derive the wave equation for the AGWs which contains the terms of acoustic wave, gravity wave, viscous dissipation and source. The source terms may be chosen in the form of the temperature (auroral heating) or the density fluctuations (precipitation) in the auroral region. We consider these fluctuations to be of Gaussian form in space centered between 100 and 120 km altitude, with the amplitude equals to 1% of the ambient. The model was applied to study the propagation characteristics of MSTIDs in the polar ionosphere on December 8, 2009 (dayside). The same MSTID was identified on a previous study using an all-sky imager in the Norwegian ionosphere. This MSTID was found to propagate equator-eastward with the average velocity of 60-100 m/s and their wavefronts were aligned in Southwest-Northeast direction. Some characteristics identified in our observations suggest that the horizontal coverage of AGWs is proportional to the horizontal Gaussian spread of the Joule heating source. It also implies that this source is capable of launching AGW which propagates long distance in latitude without much attenuation. |
