Effects of alpha-effect fluctuations on simple nonlinear dynamo models
Abstract
We investigate the interaction of a fluctuating alpha-effect with large-scale shear in a simple nonlinear 1-dimensional dynamo wave model. We firstly extend the calculations of Proctor (2007, MNRAS, 41, L39-L42) to include spatial variation of the fluctuations, and find that there can be a mechanism for magnetic field generation, even when the mean alpha is zero, provided the spatiotemporal spectrum of the fluctuations has an appropriate form. We investigate mean-field dynamo action when the new term arising from the fluctuations is non-zero, and present results concerning the stability and frequency of the solutions and parity selection in the nonlinear regime. The relation between the asymptotic theory and explicit simulation of a traditional mean-field model with a fluctuating function for the alpha-effect term is discussed.
Cite
@article{arxiv.1011.2406,
title = {Effects of alpha-effect fluctuations on simple nonlinear dynamo models},
author = {K. J. Richardson and M. R. E. Proctor},
journal= {arXiv preprint arXiv:1011.2406},
year = {2015}
}
Comments
18 pages, 10 figures, accepted in GAFD Special Issue - Natural Dynamos