COMPLEXITIES OF THE IONOSPHERIC CURRENT SYSTEM AT LOW LATITUDES

During the month of December 1975, when the mean solar daily variation of geomagnetic horizontal intensity was the lowest, an abnormally lar ge number of days had reversed counter electrojet current features at Indian longitudes. The electrojet current is shown to be a system fair ly independent of the general Sq current system. Latitudinal profiles of DELTAH and DELTAZ are described which do, not always conform to the current system of normal or counter electrojet and present complex mi xtures of the Sq and equatorial electrojet current systems. A new curr ent loop during a counter equatorial electrojet day, when a westward c urrent at low latitudes is associated with an eastward current at lati tudes higher than 12-degrees dip latitude, is suggested to be superpos ed over the normal Sq current system. It is suggested that these compl ex structures of low latitude current systems are the result of variou s tidal modes of atmospheric oscillations.