Deep minima in stellar dynamos
SVE Group, Manchester Computing, University of Manchester, Manchester M13 9PL, UK
2 Department of Mathematics, University of Manchester, Manchester M13 9PL, UK
Corresponding author: J. Brooke, email@example.com
Accepted: 10 September 2002
We study a Cartesian analogy for a solar dynamo model to investigate systematically a dynamo model limited by the back reaction of the Lorentz force on the differential rotation. In particular, we investigate intermittent behaviour found at low turbulent magnetic Prandtl numbers τ, and determine empirical scaling laws with τ. We find this class of models to be incapable of producing extended periods of “normal” behaviour separated by occasional “grand minima” – rather the behaviour is a mirror image, with occasional “grand maxima”. Further we find the existence of solar-like torsional oscillations to be incompatible with low magnetic Prandtl number intermittent regimes.
Key words: magnetic fields / magnetohydrodynamics (MHD) / Sun: magnetic fields
© ESO, 2002