North/South Asymmetry in Solar Activity and its Effects on the High Energy Cosmic Ray Diurnal Variation
Using a data base extending from 1955 through 1980, it is found that the northern hemisphere of the sun was decidedly more active than the southern hemisphere for the period 1959 through 1970. From 1971 through 1980 there was no systematic asymmetry. Extending the time period through 1984, but using a different data base, an apparent change is found around October 1982, after which there are decidedly more flares occurring in the southern hemisphere of the sun than in the northern hemisphere. Examination of the diurnal variation amplitude present in the extremely high energy (approximately 100 GeV) cosmic radiation measurements indicates a consistent north/south asymmetry until about 1971 which is believed to be the result of the asymmetric solar activity.