HR: 1340h
AN: SM53B-0427    [Abstracts]
TI: Nonlinear Alfven Wave Interactions and Three-Dimensional Alfvenic Reconnection
AU: * Song, Y
EM: yan@fields.space.umn.edu
AF: University of Minnesota, School of Physics and Astronomy, 116 Church Street, S.E., Tate Lab., Minneapolis, MN 55455 United States
AU: Lysak, R L
EM: bob@belka.space.umn.edu
AF: University of Minnesota, School of Physics and Astronomy, 116 Church Street, S.E., Tate Lab., Minneapolis, MN 55455 United States
AB: Observations in magnetospheric physics show that reconnection is a three-dimensional dynamical process often occurring in a patchy and sporadic manner and involving the energization of charged particles and the generation of Alfven waves. When fast mode wave packets or wave fronts impinge on a current sheet at the magnetopause or in the magnetotail, the fast mode wave packets can be nonlinearly converted into shear Alfven wave packets. Thus, reconnection is 3D and Alfvenic. Due to the local change of mechanical and/or magnetic stresses during the nonlinear wave mode conversion, the parallel electric fields required by the breakdown of the frozen-in condition are generated. It must be noted that the generalized Ohm's law does not reveal how parallel electric fields are generated. The generation of the parallel electric fields required by reconnection is derived from a complete set of dynamical equations including (i) Newton's law for ions and electrons and (ii) Maxwell's equations including the displacement current. The 3D Alfvenic reconnection process corresponds to a reactive, rather than a resistive, transport process, where the parallel electric field has inductive nature, causing the energization of charged particles. Radiation of kinetic Alfven waves provides the impedance allowing fast reconnection. The Poynting flux of electromagnetic energy flowing into the reconnection region is converted not only into Joule heating, the kinetic energy of plasma flows and accelerated particles, but also into electromagnetic energy associated with the Alfv‚n wave packet.
DE: 7835 Magnetic reconnection
DE: 2712 Electric fields (2411)
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 2748 Magnetotail boundary layers
DE: 2752 MHD waves and instabilities
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting