Item

Abstract

We use a novel method to show that solar radio fluxes and sunspot numbers depict a similar systematic 22-year variation in hemispheric dominance during the last 75 years. Cycle maximum radio fluxes and sunspot numbers in all odd solar cycles (19, 21, 23) are larger in the north than in the south, but smaller in all even cycles (18, 20, 22 24). This alternation indicates a new Hale-cycle related variation in solar activity and magnetic flux emergence. Hemispheric asymmetry varying at the Hale cycle gives strong evidence for the existence of a northward directed relic magnetic field, which was slightly shifted northward. Then, in odd cycles, the northern hemisphere is enhanced more than the southern hemisphere, while in even cycles, the northern hemisphere is reduced more than the southern hemisphere, establishing the observed hemispheric alternation.The shift (north-south location) of the relic oscillates at the 210-year Suess/deVries cycle around the solar equator. This leads to a centennial alternation of hemispheric asymmetry, which has earlier been evidenced in geomagnetic activity. Asymmetry maximizes when the shift is large and minimizes with no shift. This also explains the relation between asymmetry (shift) and activity. Gleissberg cycle is just one excursion of the shift, a half of the Suess/deVries cycle.We forecast that cycle 25 becomes only slightly larger than cycle 24, and cycle 26 will also remain rather small. However, cycle 27 will be much higher, and cycle 29 will be another century-high cycle. Future cycles will be notably south-dominated.