Morphology of M (3000) F2 At an African Equatorial Sector

This study examined the morphology of the ionospheric propagation factor M(3000)F2 over an African equatorial sector using long-term ionosonde observations from Korhogo, Ivory Coast. Existing published datasets covering the period from January 1993 to December 2000 were analyzed to investigate the diurnal, seasonal, and interannual characteristics of M(3000)F2. Hourly values were averaged to obtain monthly and seasonal mean profiles, and the data were classified into equinoctial and solstitial seasons to highlight systematic morphological patterns. The results showed that M(3000)F2 exhibited pronounced diurnal variability characterized by sharp post-sunrise maxima, extended daytime minima, prominent post-sunset enhancements, and sustained nighttime peaks across all seasons. Seasonally, higher M(3000)F2 values were consistently observed during the equinoxes compared to the solstices, indicating enhanced equatorial electrodynamic activity during equinoctial periods. Interannual analysis revealed that M(3000)F2 values were generally higher during years of low solar activity and reduced during years of elevated solar activity, although the fundamental diurnal structure remained largely invariant throughout the study period. These findings demonstrated that the morphology of M(3000)F2 at the African equatorial sector was primarily controlled by equatorial electrodynamic processes, including vertical plasma drifts and pre-reversal enhancement, with solar cycle conditions modulating the magnitude of variability. The study provided valuable observational evidence from a data-sparse region and contributed to improved understanding of equatorial ionospheric behavior relevant to high-frequency radio propagation and ionospheric modeling.