Multiple forms of intermittency in partial differential equation dynamo models

We find concrete evidence for the presence of crisis-induced and Pomeau-Man neville type-I intermittencies in an axisymmetric partial differential equa tion (PDE) mean-field dynamo model. These findings are of potential importa nce for two different reasons. First, as far as we are aware, this is the f irst time detailed evidence has been produced for the occurrence of these t ypes of intermittency for such deterministic PDE models. And second, despit e the rather idealized nature of these models, the concrete evidence. for t he occurrence of more than one type of intermittency in such models makes i t in principle possible that different types of intermittency may occur in different solar-type stars or even in the same star over different epochs. In this way a multiple intermittency framework may turn out to be of import ance in understanding the mechanisms responsible for grand-minima type beha vior in the Sun and solar-type stars and in particular in the interpretatio n of the corresponding observational and proxy evidence. [S1063-651X(99)088 11-X].