Convective instability of thin flux tubes.
Abstract
The stability of magnetic flux tubes embedded vertically in a convection zone is investigated. For thin tubes, the dominant instability is of the convective type, i.e. it is driven by buoyancy forces associated with displacements along the tube. The stability is determined by β = 8πP/B2; if β ≤ βc the tube is convectively stable, otherwise it is unstable, where the critical value βc depends on the stratification of the convection zone. For a solar convection zone model, βc = 1.83, corresponding to a magnetic field strength of 1350 G at the surface of the Sun. It is concluded that the flux tubes making up the small scale field of the Sun are probably hydrodynamically stable.
- Publication:
-
Solar Physics
- Pub Date:
- May 1979
- DOI:
- 10.1007/BF00150128
- Bibcode:
- 1979SoPh...62...15S
- Keywords:
-
- Convective Flow;
- Magnetic Flux;
- Magnetohydrodynamic Stability;
- Solar Magnetic Field;
- Surface Stability;
- Approximation;
- Buoyancy;
- Gas Pressure;
- Linear Equations;
- Solar Physics;
- Thermodynamic Equilibrium;
- Solar Physics;
- Field Strength;
- Magnetic Field Strength;
- Buoyancy Force;
- Flux Tube;
- Convection Zone;
- Solar Convective Zones