HR: 1340h
AN: GP33A-0930    [Abstracts]
TI: Testing Numerical Dynamo Models Against Experimental Results
AU: * Gissinger, C J
EM: christophe.gissinger@lps.ens.fr
AF: Ecole Normale Supérieure, Département de Physique, LPS, 24 rue Lhomond, Paris, 75005, France
AU: Fauve, S
EM: fauve@lps.ens.fr
AF: Ecole Normale Supérieure, Département de Physique, LPS, 24 rue Lhomond, Paris, 75005, France
AU: Dormy, E
EM: dormy@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, Equipe MAG, Ecole Normale Supérieure, Département de Physique, LRA, 24 rue Lhomond, Paris, 75005, France
AB: Significant progress has been achieved over the past few years in describing the geomagnetic field using computer models for dynamo action. Such models are so far limited to parameter regimes which are very remote from actual values relevant to the Earth core or any liquid metal (the magnetic Prandtl number is always over estimated by a factor at least 10⁴). While existing models successfully reproduce many of the magnetic observations, it is difficult to assert their validity. The recent success of an experimental homogeneous unconstrained dynamo (VKS) provides a new way to investigate dynamo action in turbulent conducting flows, but it also offers a chance to test the validity of exisiting numerical models. We use a code originaly written for the Geodynamo (Parody) and apply it to the experimental configuration. The direct comparison of simulations and experiments is of great interest to test the predictive value of numerical simulations for dynamo action. These turbulent simulations allow us to approach issues which are very relevant for geophysical dynamos, especially the competition between different magnetic modes and the dynamics of reversals.
DE: 1507 Core processes (1213, 8115)
DE: 1510 Dynamo: theories and simulations
DE: 4410 Bifurcations and attractors
DE: 4490 Turbulence (3379, 4568, 7863)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting