Alpha effect due to buoyancy instability of a magnetic layer

Details Alpha effect due to buoyancy instability of a magnetic layer Alpha effect due to buoyancy instability of a magnetic layer

2010-11-04

arxiv.org/abs/1011.1218v1

Astron. Astrophys. 534, A46 (2011)

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

14 pages, 19 figures 3 tables (submitted to A & A)

Scientific paper

10.1051/0004-6361/201016108

A strong toroidal field can exist in form of a magnetic layer in the overshoot region below the solar convection zone. This motivates a more detailed study of the magnetic buoyancy instability with rotation. We calculate the alpha effect due to helical motions caused by a disintegrating magnetic layer in a rotating density-stratified system with angular velocity Omega making an angle theta with the vertical. We also study the dependence of the alpha effect on theta and the strength of the initial magnetic field. We carry out three-dimensional hydromagnetic simulations in Cartesian geometry. A turbulent EMF due to the correlations of the small scale velocity and magnetic field is generated. We use the test-field method to calculate the transport coefficients of the inhomogeneous turbulence produced by the layer. We show that the growth rate of the instability and the twist of the magnetic field vary monotonically with the ratio of thermal conductivity to magnetic diffusivity. The resulting alpha effect is inhomogeneous and increases with the strength of the initial magnetic field. It is thus an example of an "anti-quenched" alpha effect. The alpha effect is nonlocal, requiring around 8--16 Fourier modes to reconstruct the actual EMF based on the actual mean field.

Affiliated with

Also associated with

No associations

Rating

Alpha effect due to buoyancy instability of a magnetic layer does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Alpha effect due to buoyancy instability of a magnetic layer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Alpha effect due to buoyancy instability of a magnetic layer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-146575