Large-scale convective dynamos in a stratified rotating plane layer |
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| Authors: | Krzysztof A Mizerski |
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| Institution: | 1. Department of Applied Mathematics , University of Leeds , Leeds LS2 9JT , UK;2. Department of Mechanics and Physics of Fluids , Institute of Fundamental Technological Research, Polish Academy of Sciences , Pawinskiego 5B, 02-106, Warsaw , Poland |
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| Abstract: | We study the effect of stratification on large-scale dynamo action in convecting fluids in the presence of background rotation. The fluid is confined between two horizontal planes and both boundaries are impermeable, stress-free and perfectly conducting. An asymptotic analysis is performed in the limit of rapid rotation (τ???1 where τ is the Taylor number). We analyse asymptotic magnetic dynamo solutions in rapidly rotating systems generalising the results of Soward A convection-driven dynamo I. The weak field case. Philos. Trans. R. Soc. Lond. A 1974, 275, 611–651] to include the effects of compressibility. We find that in general the presence of stratification delays the efficiency of large-scale dynamo action in this regime, leading to a reduction of the onset of dynamo action and in the nonlinear regime a diminution of the large-scale magnetic energy for flows with the same kinetic energy. |
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| Keywords: | Anelastic convection Convective dynamo Compressibility |
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