Double-diffusive instabilities of a shear-generated magnetic layer

Abstract

Previous theoretical work has speculated about the existence of double-diffusive magnetic buoyancy instabilities of a dynamically evolving horizontal magnetic layer generated by the interaction of forced vertically sheared velocity and a background vertical magnetic field. Here we confirm numerically that if the ratio of the magnetic to thermal diffusivities is sufficiently low then such instabilities can indeed exist, even for high Richardson number shear flows. Magnetic buoyancy may therefore occur via this mechanism for parameters that are likely to be relevant to the solar tachocline, where regular magnetic buoyancy instabilities are unlikely.

Submitted to ApJL

References in corpus (1)

• Flux-transport dynamos with Lorentz force feedback on differential rotation and meridional flow: Saturation mechanism and torsional oscillations

Cited by in corpus (17)

• Inverse cascade and symmetry breaking in rapidly-rotating Boussinesq convection
• Magnetic Effects in Hot Jupiter Atmospheres
• Three dimensional non-linear evolution of a magnetic flux tube in a spherical shell: Influence of turbulent convection and associated mean flows
• Dynamo action and magnetic buoyancy in convection simulations with vertical shear
• Alpha effect due to buoyancy instability of a magnetic layer
• Subcritical excitation of the current-driven Tayler instability by super-rotation
• How can large-scale twisted magnetic structures naturally emerge from buoyancy instabilities?
• Magnetic buoyancy instabilities in the presence of magnetic flux pumping at the base of the solar convection zone
• Violation of Richardson's Criterion via Introduction of a Magnetic Field
• Interactions between magnetohydrodynamic shear instabilities and convective flows in the solar interior
• Shear instabilities in a fully compressible polytropic atmosphere
• Shear-driven magnetic buoyancy in the solar tachocline: The mean electromotive force due to rotation
• Evolution of forced shear flows in polytropic atmospheres: A comparison of forcing methods and energetics
• Modeling the Parker instability in a rotating plasma screw pinch
• Rapidly Rotating Wall-Mode Convection
• Shear-driven magnetic buoyancy in the solar tachocline: Dependence of the mean electromotive force on diffusivity and latitude
• Evolution and characteristics of forced shear flows in polytropic atmospheres: Large and small Péclet number regimes