Abstract
A fully self-consistent nonlinear dynamo is studied in the limit of the low kinetic Reynolds number by adopting a simplified statistical model. Governing equations for the evolution of a mean magnetic field and correlation functions of fluctuating magnetic fields are derived for arbitrary values of the magnetic Reynolds number. Within this model, the alpha-effect is shown to be modified by the back reaction of the Lorentz force whilst the turbulent diffusivity remains the same as in the kinematic case. We also show that the nonlinear saturation of small-scale fields can come about via the suppression of the stretching property of the flow.
| Original language | English |
|---|---|
| Pages (from-to) | 232-239 |
| Number of pages | 8 |
| Journal | Physics Letters, Section A: General, Atomic and Solid State Physics |
| Volume | 259 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 16 Aug 1999 |
| Externally published | Yes |
Funding
The author would like to thank T. Bogdan, D.W. Hughes, A.D. Gilbert, P.H. Diamond, J. Herring and anonymous referees for useful comments. The National Center for Atmospheric Research is sponsored by the National Science Foundation. This work was supported in part by PPARC grant GR/K43308.
ASJC Scopus subject areas
- General Physics and Astronomy