Some Differences in the Dynamics of the Intermediate Descending Layers Observed During Periods of Maximum and Minimum Solar Flux

Autor(es)

Santos, A. M. ^[1] ; Batista, I. S. ^[1] ; Sobral, J. H. A. ^[1] ; Brum, C. G. M. ^[2] ; Abdu, M. A. ^[1] ; Souza, J. R. ^[1]

Afiliação do(s) autor(es)

^[1] Natl Inst Space Res, Sao Jose Dos Campos - Brazil

^[2] Univ Cent Florida, Arecibo Observ, Arecibo, PR - USA

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 125, n. 10 OCT 2020.
• Citações Web of Science: 0

Resumo

In this paper, ionograms from SAo Luis (SL, 2 degrees S; 44 degrees W, I: -3.8 degrees) and Cachoeira Paulista (CP, 22.42 degrees S; 45 degrees W, I: -34.4 degrees) are analyzed to examine the characteristics of the intermediate descending layers (ILs) over the Brazilian equatorial and low-latitude regions under different solar flux conditions. The solar flux effects on the ILs are investigated in terms of the rate of occurrence of the IL; the seasonal behavior of some parameters such as the height, frequency, and velocity; and the duration and the number of ILs events observed per day. One of the main results of this work is that unlike over CP, the ILs over SL presented some peculiarities, such as a lower rate of occurrence during a period of solar maximum activity (2003) when compared with a period of solar minimum activity (2009). This apparent variation was likely caused by the magnetic equator moving away from SL during this period. The duration of the ILs was also investigated, and it was found that in 2009, the ILs presented higher life time than in 2003. The descending velocity of the ILs is compatible with the semidiurnal and quarter-diurnal tides. Over SL, the larger descending rate in some cases (>10 km/hr) may reveal the additional influence of the gravity waves in the IL's dynamics. (AU)

• Processo FAPESP: 15/25357-4 - Climatologia das camadas intermediárias sobre o setor equatorial e de baixas latitudes brasileiras
• Beneficiário: Angela Machado dos Santos Valentim
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/50115-0 - INCT 2014: tecnologia GNSS no suporte à navegação aérea
• Beneficiário: Joao Francisco Galera Monico
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisa em Políticas Públicas