Magnetic field twisting by intergranular downdrafts
|Number of pages||11|
|Early online date||28 Sept 2016|
|Publication status||Published - 01 Oct 2016|
Show download statistics Citation formats
The interaction of an intergranular downdraft with an embedded vertical magnetic field is examined. It is demonstrated that the downdraft may couple to small magnetic twists leading to an instability. The descending plasma exponentially amplifies the magnetic twists when it decelerates with depth due to increasing density. Most efficient amplification is found in the vicinity of the level, where the kinetic energy density of the downdraft reaches equipartition with the magnetic energy density. Continual extraction of energy from the decelerating plasma and growth in the total azimuthal energy occurs as a consequence of the wave-flow coupling along the downdraft. The presented mechanism may drive vortices and torsional motions that have been detected between granules and in simulations of magnetoconvection.
- instabilities, magnetohydrodynamics (MHD), Sun: granulation, Sun: interior, Sun: magnetic fields, Sun: photosphere
Show more files.. Show less files..
- Magnetic field twisting by intergranular downdrafts
Final published version, 783 KB, PDF
Licence: CC BY-NC Show licence