Equatorial electrojet and regular daily variation SR—IV. Special features in particular days

Abstract

Special features of the regular daily variation S R in the region of the equatorial electrojet are set forth from magnetic H and Z profiles for each local hour of particular days. It is pointed out that afternoon low-latitude negative disturbances in H are not amplified along the dip equator whereas irregular fluctuations are amplified and tend to inhibit the variation S R . Examples of the day-to-day variability are displayed for consecutive days; some of them can be related to the presence of a counter-electrojet, others to the effect of neutral winds. Finally, strong counter electrojet events are discussed.