Effects of magnetic and sunspot activities on the topside ionosphere

Results of a study of the scale heights and transition levels in the scale height for magnetically quiet and disturbed conditions for the years 1962-64 for the latitude range 40-70 deg N (geomag. lat.) during the interval 1400-1600 hrs LMT are presented. From a study of the latitudinal variations of the ratio of scale heights for quiet and disturbed days in the height ranges 300-500 and 800-1000 km it is found that this ratio increases with increase of latitude in all the sunspot epochs considered from 40 to 60 N. The latitudinal variations of the transition level in the scale height shows a peak around 55-60 deg N, i.e., around the trough in all the years during disturbed days only.