The sun's magnetic field changes polarity approximately every 11 years.
The sun’s magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun’s inner magnetic dynamo re-organizes itself. The sun’s polar magnetic fields weaken, go to zero and then emerge again with the opposite polarity. This is a regular part of the solar cycle.
View associated news item at https://www.nasa.gov/content/goddard/the-suns-magnetic-field-is-about-to-…