Jörn Warnecke, Petri J. Käpylä, Maarit. J. Mantere, Axel Brandenburg
We combine a convectively driven dynamo in a spherical shell with an
isothermal density-stratified exterior that mimics a stellar corona to study
the emergence and ejections of magnetic field structures. This approach is an
extension of earlier models where we employed forced turbulence simulations to
generate magnetic fields. A spherical wedge is used which consists of a
convection zone and a corona up to more than twice the radius of the sphere.
The wedge contains a quarter of the azimuthal extent of the sphere and
150\degree in latitude.The magnetic field is self-consistently generated by the
turbulent motions due to convection underneath the surface. Magnetic fields are
found to emerge at the surface and are ejected to the coronal part of the
domain. These ejections occur in irregular intervals and are smaller than in
earlier work. We associate these events with coronal mass ejections on the Sun.
View original:
http://arxiv.org/abs/1112.0505
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