Tidally synchronized Tayler-Spruit dynamos


Tidally synchronized Tayler-Spruit dynamos

Stefani, F.; Galindo, V.; Giesecke, A.; Weber, N.; Weier, T.

The dynamo loop in Tayler-Spruit models for the generation of stellar magnetic fields can only be closed if the kink-type Tayler instability (TI) goes along with some alpha effect. While for large magnetic Prandtl numbers (Pm) some finite alpha can easily result from spontaneous symmetry breaking, low Pm systems show typically a vanishing or an oscillatory alpha effect. If the TI, with its typical m=1 azimuthal dependence, is exposed to an m=2 tidal forcing, we observe a sharp resonance if the tidal frequency equals the frequency of theintrinsic alpha oscillation. In the framework of a very simple alpha-Omega dynamo model we further show that this resonance can lead to synchronization of the dynamo. We also discuss the hypothetical possibility that this mechanism could link the 11.07 year periodicity of the tidally dominant Venus-Earth-Jupiter system with the Hale cycle of the solar magnetic field.

  • Lecture (Conference)
    17th MHD Days, 30.11.-02.12.2016, Göttingen, Germany

Permalink: https://www.hzdr.de/publications/Publ-24923
Publ.-Id: 24923