Effects of Geomagnetic Storm Classes on the Ionosphere at Korhogo Station

This work is a study of the effects of geomagnetic storm classes on the ionosphere at the Korhogo station (Lat. 9.3˚N; Long. 354.6˚E; dip. 0.6˚S). The years covered by the study are 1993, 1995, 1998, and 2001. The ionospheric parameter used is the critical frequency of the F2 layer of the ionosphere (foF2). The geomagnetic storm classes considered are weak storms, moderate storms, and intense storms. The study of the effects on the diurnal profiles of foF2 is carried out by comparing the profiles of storm periods with those of periods without storms. The occurrence and intensity of ionospheric storms generated by geomagnetic storms are studied from the formula of the deviation relation of foF2 in disturbed periods compared to periods without storms (ΔfoF2). The results show that weak storms have no significant effect on all types of diurnal foF2 profiles. Moderate and intense storms disrupt the “noon bite out” profiles but do not disrupt the other types of profiles. The analysis of the evolution of ΔfoF2 shows that all classes of magnetic storms generate positive storms whose peaks are more pronounced in the night-morning sector (45%, 50%, 78%). Moderate and intense storms sometimes generate negative storms in the night-morning sector. Positive storms are more intense during intense storms, but negative storms are more intense during moderate storms.