Re: Sunspots - cause?
Sunspots are relatively cool areas that appear as dark blemishes on the face of the sun. They are formed when magnetic field lines just below the sun's surface are twisted and poke though the solar photosphere. The twisted magnetic field above sunspots are sites where solar flares are observed to occur, and we are now beginning to understand the connection between solar flares and sunspots.
http://www.sunspotcycle.com/