Latitudinal Variation of Electron Density in the Topside Ionosphere

214-217The results of an analysis of the latitudinal variations of Ne are presented, with the data obtained from Alouette-I topside sounder satellite passes. With the increase of latitude the electron density falls from a higher value to a minimum with a trough around 70ᵒN geomagnetic latitude (60ᵒN geographic latitude) and has a tendency of increasing again above 70ᵒN. The rate of fall is more pronounced at the lower latitudes of the satellite. This phenomenon is also observed during the disturbed days; but, in general, there will be an enhancement of Ne at all heights in the lower topside ionosphere for which a possible explanation is given