This paper deals with TEC variability during fluctuating geomagnetic events (FE) during solar cycle 24 at Koudougou station (lat: 12<sup>o</sup>15'N;Geo long: -2<sup>o</sup>20'E). The s...This paper deals with TEC variability during fluctuating geomagnetic events (FE) during solar cycle 24 at Koudougou station (lat: 12<sup>o</sup>15'N;Geo long: -2<sup>o</sup>20'E). The study was done by comparing TEC variations during FE days with those of quiet days (QA). Comparison was made taking into account solar phases’ and seasons’ influences. FE’s and QA’s TEC curves are characterized by dome profiles. All graphs show two troughs, one in the morning (0500 LT) and the second in the evening (around 2000 LT) and a peak around 1400 LT during all solar phases and winter months and around 1500 LT for the remaining seasons. Both troughs are caused by the decrease of the photo ionization and an increase of the recombination phenomena, as well for FE as for QA periods. FE cause positive storms during all solar phases as well as during seasons and some negative storms during spring and summer months and minimum and maximum solar phases.展开更多
This work is a study of the effects of geomagnetic storm classes on the iono-sphere 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 p...This work is a study of the effects of geomagnetic storm classes on the iono-sphere 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 param-eter 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 car-ried out by comparing the profiles of storm periods with those of periods with-out 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 ofΔfoF2 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.展开更多
文摘This paper deals with TEC variability during fluctuating geomagnetic events (FE) during solar cycle 24 at Koudougou station (lat: 12<sup>o</sup>15'N;Geo long: -2<sup>o</sup>20'E). The study was done by comparing TEC variations during FE days with those of quiet days (QA). Comparison was made taking into account solar phases’ and seasons’ influences. FE’s and QA’s TEC curves are characterized by dome profiles. All graphs show two troughs, one in the morning (0500 LT) and the second in the evening (around 2000 LT) and a peak around 1400 LT during all solar phases and winter months and around 1500 LT for the remaining seasons. Both troughs are caused by the decrease of the photo ionization and an increase of the recombination phenomena, as well for FE as for QA periods. FE cause positive storms during all solar phases as well as during seasons and some negative storms during spring and summer months and minimum and maximum solar phases.
文摘This work is a study of the effects of geomagnetic storm classes on the iono-sphere 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 param-eter 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 car-ried out by comparing the profiles of storm periods with those of periods with-out 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 ofΔfoF2 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.
