For decades to come, the limits to computing power will not allow atomistic simulations of macroscopic specimens. Simulations can only be performed on various scales (nano, meso, micro and macro) using the input provided by simulations (or data) on the next smaller scale. The resulting hierarchy has been the focus of many seminars and lectures. Necessarily, special emphasis has been placed on mesoscopic simulations, bridging the gaps between nano (atomic) and micro space and time scales."

This volume contains the invited papers presented at the NATO Advanced Research Workshop on the Theory of Sunspots, held in Cambridge, England, 22-27 September 1991. The idea of holding this Workshop first arose during the Solar Optical Telescope work shop on Theoretical Problems in High-Resolution Solar Physics in Munich in 1985. At that meeting, separate discussion groups were formed to consider specific topics in solar physics. The discussion group on sunspots recommended that there be a meeting devoted to theoretical problems associated with sunspots, the motivation being the consensus...