We examine global dynamics and bifurcations occurring in a truncated model of
a stellar mean field dynamo. This model has symmetry-forced invariant subspaces
for the dynamics and we find examples of transient type I intermittency and
blowout bifurcations to transient on-off intermittency, involving laminar
phases in the invariant submanifold. In particular, our model provides examples
of blowout bifurcations that occur on varying a non-normal parameter; that is,
the parameter varies the dynamics within the invariant subspace at the same
time as the dynamics normal to it. As a consequence of this we find that the
Lyapunov exponents do not vary smoothly and the blowout bifurcation occurs over
a range of parameter values rather than a point in the parameter space.Comment: Full paper with figures, also available on the web page
http://www.maths.qmw.ac.uk/~eoc. Physical Review E, accepte
