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On a Physically Realistic Fast Dynamo

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Abstract

As a step towards a physically realistic model of a fast dynamo, we study numerically a kinematic dynamo driven by convection in a rapidly rotating cylindrical annulus. Convection maintains the quasi-geostrophic balance whilst developing more complicated time-dependence as the Rayleigh number is increased. We incorporate the effects of Ekman suction and investigate dynamo action resulting from a chaotic flow obtained in this manner. We examine the growth rate as a function of magnetic Prandtl number Pm, which is proportional to the magnetic Reynolds number. Even for the largest value of Pm considered, a clearly identifiable asymptotic behaviour is not established. Nevertheless the available evidence strongly suggests a fast dynamo process.

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Authors and Affiliations

  1. Department of Applied Mathematics, University of Leeds, Leeds, UK

    Eun-Jin Kim & D. W. Hughes

  2. Department of Mathematics, University of Exeter, Exeter, UK

    A. M. Soward

Authors
  1. Eun-Jin Kim
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  2. D. W. Hughes
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  3. A. M. Soward
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Kim, EJ., Hughes, D.W. & Soward, A.M. On a Physically Realistic Fast Dynamo. Studia Geophysica et Geodaetica 42, 335–342 (1998). https://doi.org/10.1023/A:1023360821539

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  • DOI: https://doi.org/10.1023/A:1023360821539

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