Magnetic field reversals in nature, experiments and simulations


Magnetic field reversals in nature, experiments and simulations

Giesecke, A.; Stefani, F.; Gerbeth, G.

From paleomagnetic observations, numerical simulations and -- meanwhile -- also experiments, it appears that reversing dynamos are a quite common phenomenon.
Long time series of mean field simulations adopting Earth-like parameters yield reversal sequences whose statistical behavior is comparable to the Earth.
Recent hints for a reversing experimental dynamo give reason for the examination of a cylindrical dynamo with simulations that are especially suited to the experimental conditions.
This requires a numerical scheme that is able to treat insulating boundary conditions and material properties like permeability and/or conductivity jumps.
Preliminary calculations including a high permeability zone show a slight reduction of the critical Reynolds number.
In future simulations permeability jumps will be increased and an alpha-effect describing the inductive action of turbulence will be included.

Keywords: Reversals; Geodynamo; Simulations

  • Lecture (Conference)
    ICTAM2008 - International Congress of Theoretical and Applied Mechanics, 25.-29.08.2008, Adelaide, Australia
  • Contribution to proceedings
    ICTAM2008 - International Congress of Theoretical and Applied Mechanics, 25.08.-29.09.2008, Adelaide, Australien, 978-0-9805142-1-6

Permalink: https://www.hzdr.de/publications/Publ-11571
Publ.-Id: 11571