Solar flare effects on the geomagnetic elements during normal and counter electrojet periods

Abstract

During a strong and normal electrojet event time, sfeconsists of a positive impulse in Hat all stations, the amplitude of Hfollowing the latitudinal variation similar to that of the quiet day monthly mean, Sq(H). The sfein Yis negative at all the stations. Sfein Zshows positive impulse at the four-electrojet stations and negative at other stations. During a counter electrojet period the effect of solar flare on Hfield is negative impulse at electrojet stations, positive at low latitude and again negative at stations north of Sqfocus. Sfein Yis small at all the equatorial and negative at higher latitude stations. However, sfe(Z) is negative at the equatorial latitudes.During a partial counter electrojet period the observed effect is the combination of an increase of the planetary current component and the decrease of the electrojet component, giving rise to a negative impulse in Hat equatorial stations and a positive impulse in H, increasing with increasing distance from the equator. These results are presented and discussed.