Variability of the Critical Frequency foF2 for Equatorial Regions during Solar Cycle’s Minima and Maxima at Ouagadougou and Manila Stations

HTML  XML Download Download as PDF (Size: 2989KB)  PP. 833-844  
DOI: 10.4236/ijg.2019.1010047    464 Downloads   1,243 Views  Citations

ABSTRACT

In this paper we report on the foF2 variabilities for two equatorial regions (Ouagadougou: Lat. 12.4°N; Long. 358.5°E, Dip. 1.43°S; and Manila: Lat. 14°36'15.12''N; Long. 120°58'55.92''E; Dip. 0.6°S) during solar cycles 20 and 21 minima and maxima phases. Many previous works have argued on the diurnal and seasonal variation of foF2 for different solar events conditions for latitudinal position. But there are few investigations for Africa equatorial region longitudinal variation. The present paper’s goal is to outline possible similarity in foF2 behavior between variations for better understanding of physical process lead to some observed phenomenon in Asia-Africa equatorial sector. The F-layer critical frequency (foF2) data observed from the two equatorial ionosonde stations have been used for the present comparative study. The results show significant similarity between the critical frequency (foF2) seasonal variations over the time intervals 1976-1996. During day-time measured data from Manila station are higher than those from Ouagadougou station. That may lie in that Manila is closer to equatorial ionization crest region. During solar minimum phase, the longitudinal variation of foF2 shows two crossing points (11:00 UT and 22:00 UT) between the foF2 profiles form the two stations for all seasons regardless of the solar cycle. However during intense solar activity condition, the number of crossing-point between measured data from Manila and Ouagadougou stations varies by seasons and solar cycle. This phenomenon may be due to the compilations of severe activities (storms, coronal mass ejection, heliosheet fluctuations) during the solar maximum phases.

Share and Cite:

M’Bi, K. , Louis, Z. , Christian, Z. and Frédéric, O. (2019) Variability of the Critical Frequency foF2 for Equatorial Regions during Solar Cycle’s Minima and Maxima at Ouagadougou and Manila Stations. International Journal of Geosciences, 10, 833-844. doi: 10.4236/ijg.2019.1010047.

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.