Babcock Model

 

 

 

1) Magnetic field is poloidal. 
2) Differential rotation creates a toroidal component. 
3) When this Toroidal component is sufficiently large, sunspots form. 
4) When the magnetic field of decaying active regions moves toward the equator and cancels with field of opposite polarity coming from the other side, and part moves to the poles, cancellations occur. The Sun has again a poloidal magnetic field but now of the opposite polarity as before. 
5) The solar cycle then repeats.