Hale cycle
The Hale cycle is the 22.1-year cycle of solar activity . It is composed of two 11-year phases of opposite magnetic polarity , as George Ellery Hale demonstrated spectroscopically in 1908 .
The Hale cycle is the 22.1-year cycle of solar activity . It is composed of two 11-year phases of opposite magnetic polarity , as George Ellery Hale demonstrated spectroscopically in 1908 .