Major ionospheric storms during July–September 1982 at lower latitudes in East Asia

Abstract

The period July–September 1982 was the peak of geomagnetic activity during the 21st solar cycle. There were four very severe storms, which covered the strongest period of geomagnetic disturbances seen in recent years, namely the storms on 13/14 July, 7 August, 6/7 September and 21/22 September 1982. The present paper analyzes the corresponding ionospheric behaviour during these major magnetic storms, along with the storms that occurred around the local summer months during the preceding years within both hemispheres of the East Asia-Oceanian sector. It is shown that during the summer months in the low-latitudes and lower mid-latitudes of this sector the strong geomagnetic storms generally result in depletion of the ionospheric electron content and electron concentration at the F-region peak during both day-time and night-time. The situation in summer is quite different from other seasons and is basically unrelated to SSC time or/and maximum disturbance time and duration.