On the Major Solar Flare Activity in Solar Cycles 19, 20 & 21 (1955-79)

Abstract

Utilizing the major solar flare data for the period 1955-79, which includes solar cycles 19, 20 and 21, a comprehensive analysis of these flares is presented. In this analysis, study is made of their distribution around the sun. both in latitude and longitude, the time latitude occurrence in solar cycles 19, 20 and 21 and their nature and frequency in northern and southern hemispheres in these solar cycles. and the change of occurrence of these flares in the course of years for both halves of the solar disk separately and also for the disk as a whole. Their relationship with sunspot numbers in different solar cycles and their occurrence frequency with increasing comprehensive flare index in general and for cycles 19 and 20 in particular (observations for cycle 21 are not complete) have also been studied.