Bibcode
Schussler, M.; Caligari, P.; Ferriz-Mas, A.; Moreno-Insertis, F.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 281, no. 2, p. L69-L72
Advertised on:
1
1994
Citations
188
Refereed citations
157
Description
We present a consistent model of storage, instability and dynamical
eruption of magnetic flux tubes in the solar convection zone and
underlying overshoot region. Using a convection zone model with
self-consistent overshoot layer, we calculate equilibrium configurations
of magnetic flux tubes and determine their linear stability properties,
taking into consideration the effects of stratification and rotation.
Instability of flux tubes stored in the overshoot layer with growth
times below one year requires field strengths of the order of
105 G; in many cases, the dominant mode has an azimuthal wave
number of m = 2. Numerical simulations are used to follow the nonlinear
evolution of such unstable flux tubes and their rise through the
convection zone, from which they emerge to form active regions. The
results are in accordance with the following two requirements, based on
observational facts: (a) the upward motion of the tubes is not
significantly deflected by the Coriolis force so that they can emerge at
low latitudes, (b) their inclination with respect to the East-West
direction (tilt angle) as a function of the latitude of emergence is
consistent with observations of acitve regions.