Coronal ejections from convective spherical shell dynamos

by Mr Jörn Warnecke (Nordita)

Wednesday 14 Dec 2011, 13:30 → 14:30 Europe/Stockholm

122:026

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 150º 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.

see 1112.0505.