Wednesday, April 15, 2020
Momentum Management Maneuver #37 Today
Thursday, April 2, 2020
Hale’s Polarity Law in Solar Cycle 25
On the right is a magnetogram from April 2, 2020. A high-latitude active region (AR 12759) has the outward field is leading the active region and the inward magnetic field is behind. AR 12759 is at 28 N (the same latitude as Cape Canaveral, FL, SDO’s launch site).
Hale’s Polarity Law is one of the reasons for the confusing names of the solar cycle. People see an 11-year sunspot cycle when they look only at sunspots. The reversal of the leading and trailing fields means that two sunspot cycles are necessary for the Sun to return to the same conditions (the 22-year solar cycle). But we still count Solar Cycles. So Solar Cycle 25 is the 25th sunspot cycle since records the numbering began in 1755.
The high-latitude, oppositely-directed field active region AR 12759 is just the beginning of Solar Cycle 25.The leading field is an outie!