Magnetic field reversals and long-time memory in conducting flows.
Employing a simple ideal magnetohydrodynamic model in spherical geometry, we show that the presence of either rotation or finite magnetic helicity is sufficient to induce dynamical reversals of the magnetic dipole moment. The statistical character of the model is similar to that of terrestrial magnetic field reversals, with the similarity being stronger when rotation is present. The connection between long-time correlations, 1/f noise, and statistics of reversals is supported, consistent with earlier suggestions.
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina.
P
P
Dmitruk
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Buenos Aires, Argentina.
P D
PD
Mininni
Department of Atmospheric and Space Physics, University of Colorado and National Center for Atmospheric Research, Boulder, Colorado, USA.
A
A
Pouquet
Dipartimento di Fisica, Universita della Calabria, Cosenza, Italy.
S
S
Servidio
Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware, USA.
W H
WH
Matthaeus