Long-term Evolution of Large-scale Magnetic Fields in Rotating Stratified Convection

Abstract

Convective dynamo simulations are performed in local Cartesian geometry. We report the first successful simulation of a large-scale oscillatory dynamo in rigidly rotating convection without stably stratified layers. A key requirement for exciting the large-scale dynamo is a sufficiently long integration time comparable to the ohmic diffusion time. By comparing two models with and without stably stratified layers, their effect on the large-scale dynamo is also studied. The spatiotemporal evolution of the large-scale magnetic field is similar in both models. However, it is intriguing that the magnetic cycle is much shorter in the model without the stable layer than with the stable layer. This suggests that the stable layer impedes the cyclic variations of the large-scale magnetic field.

arXiv comment5 pages, 4 figures, accepted to PASJ [Hinode Special Issue]

References in corpus (13)

• Astrophysical magnetic fields and nonlinear dynamo theory
• The inverse cascade and nonlinear alpha-effect in simulations of isotropic helical hydromagnetic turbulence
• Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope
• Constraints on the magnitude of alpha in dynamo theory
• Current status of turbulent dynamo theory: From large-scale to small-scale dynamos
• Large-scale dynamos in turbulent convection with shear
• Convective dynamos in spherical wedge geometry
• Large-scale dynamos in rigidly rotating turbulent convection
• Effects of Penetrative Convection on Solar Dynamo
• Do spherical alpha^2-dynamos oscillate?
• On the problem of large-scale magnetic field generation in rotating compressible convection
• Oscillatory large-scale dynamos from Cartesian convection simulations
• The helicity constraint in spherical shell dynamos

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