Periodic variation of the North-South asymmetry of solar activity phenomena

Abstract

We report here a study of various solar activity phenomena occurring in both north and south hemispheres of the Sun during solar cycles 8-23. In the study we have used sunspot data for the period 1832-1976, flare index data for the period 1936-1993, Hα flare data 1993-1998 and solar active prominences data for the period 1957-1998. Earlier Verma reported long-term cycle period in N-S asymmetry and also that the N-S asymmetry of solar activity phenomena during solar cycles 21, 22, 23 and 24 will be south dominated and the N-S asymmetry will shift to north hemisphere in solar cycle 25. The present study shows that the N-S asymmetry during solar cycles 22 and 23 are southern dominated as suggested by Verma.