Large-scale convective dynamos in a stratified rotating plane layer

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 li...

Full description

Saved in:
Bibliographic Details
Published in:Geophysical and astrophysical fluid dynamics 2013-02, Vol.107 (1-2), p.218-243
Main Authors: Mizerski, Krzysztof A., Tobias, Steven M.
Format: Article
Language:English
Subjects:
Anelastic convection
Astrophysics
Asymptotic methods
Asymptotic properties
Compressibility
Convective dynamo
Fluid dynamics
Fluid flow
Fluids
Kinetics
Magnetic fields
Planes
Rotating
Rotating generators
Stratification
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0309-1929
1029-0419
DOI:10.1080/03091929.2012.672567