HR: 0800h
AN: GP31A-0079    [Abstracts]
TI: Nonlocal memory effect of electromotive force by fluid motion with two-dimensional periodicity
AU: * Hori, K
EM: hori@eps.nagoya-u.ac.jp
AF: Kumiko Hori, Dept.Earth & Planetary sci., Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AB: The problem of how the small-scale magnetic field generates the large-scale magnetic field has not been completely solved, regardless of many recent MHD dynamo simulations. Usually the process is explained in terms of the local instantaneous alpha-effect, which approximates the electromotive force. It is not, however, obvious whether this approximation is appropriate. We examine the properties of the electromotive force by a kinematic dynamo model with a steady two-dimensional flow. We obtain that the electromotive force for the Earth's core has nonlocal memory effects, which generate magnetic fields stronger than there produced by the local instantaneous alpha-effect.
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1510 Dynamo: theories and simulations
DE: 1595 Planetary magnetism: all frequencies and wavelengths
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005