HR: 1340h
AN: SH44A-1714    [Abstracts]
TI: Breakdown of the Frozen-in Condition and Plasma Acceleration: Dynamical Theory
AU: * Song, Y
EM: yan@fields.space.umn.edu
AF: School of Physics and Astronomy, University of Minnesota, 116 Church Street, S.E., Minneapolis, MN 55455, United States
AU: Lysak, R L
EM: bob@fields.space.umn.edu
AF: School of Physics and Astronomy, University of Minnesota, 116 Church Street, S.E., Minneapolis, MN 55455, United States
AB: The magnetic reconnection hypothesis emphasizes the importance of the breakdown of the frozen-in condition, explains the strong dependence of the geomagnetic activity on the IMF, and approximates an average qualitative description for many IMF controlled effects in magnetospheric physics. However, some important theoretical aspects of reconnection, including its definition, have not been carefully examined. The crucial components of such models, such as the largely-accepted X-line reconnection picture and the broadly-used explanations of the breakdown of the frozen-in condition, lack complete theoretical support. The important irreversible reactive interaction is intrinsically excluded and overlooked in most reconnection models. The generation of parallel electric fields must be the result of a reactive plasma interaction, which is associated with the temporal changes and spatial gradients of magnetic and velocity shears (Song and Lysak, 2006). Unlike previous descriptions of the magnetic reconnection process, which depend on dissipative-type coefficients or some passive terms in the generalized Ohm's law, the reactive interaction is a dynamical process, which favors localized high magnetic and/or mechanical stresses and a low plasma density. The reactive interaction is often closely associated with the radiation of shear Alfvén waves and is independent of any assumed dissipation coefficients. The generated parallel electric field makes an irreversible conversion between magnetic energy and the kinetic energy of the accelerated plasma and the bulk flow. We demonstrate how the reactive interaction, e.g., the nonlinear interaction of MHD mesoscale wave packets at current sheets and in the auroral acceleration region, can create and support parallel electric fields, causing the breakdown of the frozen-in condition and plasma acceleration.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 7807 Charged particle motion and acceleration
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7845 Particle acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting