On the role of tidal winds in the descending of the high type of sporadic layer (Es-h)

Autor(es)

Conceicao-Santos, Fredson ; Muella, Marcio T. A. H. ; Resende, Laysa C. A. ; Fagundes, Paulo R. ; Andrioli, Vania F. ; Batista, Paulo P. ; Carrasco, Alexander J.

• Tipo de documento: Artigo Científico
• Fonte: Advances in Space Research; v. 65, n. 9, p. 17-pg., 2020-05-01.

Resumo

As the prevailing tidal winds in the E region are generated by heating mechanisms, the dynamics of Es layers impacted by solar tides is a relevant theme in the space weather studies. This paper aims to identify the tidal wind component involved in the mechanism of formation and descending of the high type of sporadic layer (Es-h). The Es-h layers observed at altitudes between around 120 and 150 km in the Brazilian low latitude stations of Jatai and Sao Jose dos Campos during the months of April, June, September and December of 2016 are used in this analysis. The height variability and altitude descent of the Es-h layers are analyzed from the h'Es parameter obtained by ionosonde data. In this study, the observational data are compared with the simulations generated by an extended version of the Ionospheric E-Region Model (MIRE). At higher altitudes in the E region, the results show that the prevailing tidal pattern and wind direction controlling the Es-h layer formation and descent are different depending on month: (a) in April and June the zonal wind component and the associated semidiurnal tidal oscillations prevail, with some differences in terms of time of occurrence and descending speeds, and (b) in September and December the diurnal tidal periodicities become dominant, and both the meridional and zonal wind components seem to control the descending of the Es(h )layers. Since the role of the tidal periodicities and wind directions changed depending on the month, the results suggest a possible seasonal tidal wind pattern, which is not well understood from the present study but requires further investigation. Other relevant aspects of the observations and the modeling are highlighted and discussed. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 18/15973-8 - VII SBGEA - Simpósio Brasileiro de Geofísica Espacial e Aeronomia
• Beneficiário: Paulo Roberto Fagundes
• Modalidade de apoio: Auxílio Organização - Reunião Científica
• Processo FAPESP: 12/08445-9 - Estudo da variabilidade dia-a-dia da mesosfera, termosfera e ionosfera em baixas latitudes e região equatorial, durante o ciclo solar 24
• Beneficiário: Paulo Roberto Fagundes
• Modalidade de apoio: Auxílio à Pesquisa - Temático