Abstract:
Using quarter-hourly ionogram data at Kodaikanal (geomag. lat: 0.6°N; dip:
3•S0N) for the period 19.57-63 a study is made of the effect of
geomagnetic activity on the occurrence of range and frequency types of
spread-F. It is found that the occurrence of both range and frequency
types of spread-F shows a significant negative correlation with
geomagnetic activity but only during years of high sunspot activity.
