How does the Suns rotation cause sunspots and magnetic field reversals?
The gases in the Sun rotate faster at the equator than the poles. Also, the interior of the Sun has gas which is convecting energy to the surface like the water in a boiling pot. Subsurface magnetic field ‘lines’ are trapped in the gas and two things happen. First, the differential rotation of the surface causes the magnetic field lines to get stretched and wrapped around the min- latitude regions of the Sun, becoming more and more concentrated towards the lower latitudes as the solar cycle progress. Concentrated sub-surface magnetic fields become ‘buoyant with respect to the gas, and as they rise to the surface, the convection and rotation cause these magnetic fields to get cyclonically twisted. When they punch through the surface, the magnetic fields produce pairs with opposite polarity. The orientation of the sunspot magnetic fields relative to the magnetic hemisphere they are in, is reversed with the S-pole leading the spot in the North magnetic hemisphere, and the opposite true in
