Terry wrote a great answer to this for a previous Solar Week. http://www.solarweek.org/CS/t/45.aspx The short answer is we don't know. We know that sunspots go through an 11 year cycle, they fist start appearing at about 30 degrees latitude and as the cycle near completion they end up all falling along the equator. This forms what we call a butterfly diagram, but why they don't appear at the poles is not fully understood, but one of the questions we are trying to answer. More about the butterfly diagram can be found here http://earthobservatory.n...arMax/solarmax_3.php