Simple Mechanism for Reversals of Earth's Magnetic Field

François Pétrélis (1) , Stéphan Fauve (1) , Emmanuel Dormy (1, 2) , Jean-Pierre Valet (2)

1 ENS-PSL - École normale supérieure - Paris
2 IPGP - Institut de Physique du Globe de Paris

We show that a model, recently used to describe all the dynamical regimes of the magnetic field generated by the dynamo effect in the von Kármán sodium experiment, also provides a simple explanation of the reversals of Earth’s magnetic field, despite strong differences between both systems. The validity of the model relies on the smallness of the magnetic Prandtl number.

Domaines: Planète et Univers [physics]

François Pétrélis, Stéphan Fauve, Emmanuel Dormy, Jean-Pierre Valet. Simple Mechanism for Reversals of Earth's Magnetic Field. Physical Review Letters, 2009, 102, ⟨10.1103/PhysRevLett.102.144503⟩. ⟨insu-03604908⟩