Axisymmetric mean field dynamos with dynamic and algebraic alpha -quenchings
Abstract
We study axisymmetric mean field spherical and spherical shell dynamo models, with both dynamic and algebraic alpha -quenchings. Our results show that there are qualitative as well as quantitative differences and similarities between these models. Regarding similarities, both groups of models exhibit symmetric, antisymmetric and mixed modes of behaviour. As regards differences, the important feature in the full sphere models is the occurrence of chaotic behaviour in the algebraic alpha -quenching models. For the spherical shell models with dynamic alpha the main features include the possibility of multi-attractor regimes with final state sensitivity with respect to small changes in the magnitude of alpha and the initial parity. We find the effect of introducing a dynamic alpha is likely to be complicated and depend on the region of the parameter space considered, rather than a uniform change towards simplicity or complexity.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1998
- DOI:
- 10.48550/arXiv.astro-ph/9709062
- arXiv:
- arXiv:astro-ph/9709062
- Bibcode:
- 1998A&A...329..350C
- Keywords:
-
- MHD;
- SUN: MAGNETIC FIELDS;
- STARS: MAGNETIC FIELDS;
- Astrophysics
- E-Print:
- Latex with full figures, also available on web page http://www.maths.qmw.ac.uk/~eoc