Why does the Sun’s magnetic polarity cycle take about 22 years?

The Sun’s magnetic polarity cycle is approximately 22 years because it consists of two consecutive 11-year sunspot cycles.12

While the number and size of sunspots fluctuate in a regular 11-year period, the magnetic polarity configuration of these sunspot groups reverses with each new cycle. Specifically, in a given hemisphere, the magnetic polarity of the leading and following spots in a pair remains consistent throughout one 11-year cycle but is reversed in the next.12

Because the magnetic polarity configuration of the sunspot groups returns to its original state only after two 11-year cycles have passed, the complete magnetic cycle is considered to be 22 years long. During this process, the magnetic fields of the follower spots drift toward the Sun’s poles, eventually reversing the dominant polar field, which in turn sets the polarity for the leading spots of the subsequent cycle.12