The north-south distribution of major solar flare events, sunspot magnetic classes and sunspot areas (1955 1974)

The north-south incidence has been studied of 31 white-light flares observed since 1859 and of 1669 events meeting the criteria for `major flares' of Dodson and Hedeman (1971) for the period 1955-1974. The asymmetry in favor of the northern hemisphere increases strikingly with the importance of the events. Similarly, magnetically complex sunspot groups (Mt. Wilson classesβγ,γ andδ) display a more pronounced asymmetry in favor of the north than non-complex groups for 1962-1970. Contrary to the flare asymmetry, the spottedness asymmetry is independent of the size of sunspots.