A new model of the solar cycle

A new model of the solar magnetic activity cycle is proposed. The model is based on the symmetries of a rotating star, and describes the interaction between dipole and quadrupole fields in the weakly non-linear regime. The model describes not only pure dipole and quadrupole dynamos, but also the transitions with increasing dynamo number to mixed polarity states, and in appropriate regimes to aperiodic states which are highly suggestive of prolonged activity minima such as the Maunder minimum.