Note on the Observed Differences in Spottedness of the Sun's Northern and Southern Hemispheres

Abstract

The variation with time of the relative spottedness of the Sun's two hemispheres, north and south, is examined by means of a simple index over a period embracing eleven 11-year sunspot cycles. There are changes from cycle to cycle which, although not random, appear to have no definite period. There is the suggestion of a dependence of the pattern of the excess spottedness, north or south, upon the degree of activity of any particular cycle. The results indicate no dependence upon a 22-year cycle.