HR: 1330h
AN: SM23B-01    [Abstracts]
TI: Alfven Wave Resonance Cone Propagation
AU: * Khazanov, I
EM: khazanov@eng.uah.edu
AF: The University of Alabama in Huntsville, 301 Sparkman Dr, Huntsville, AL 35899 United States
AU: Singh, N
EM: singh@eng.uah.edu
AF: The University of Alabama in Huntsville, 301 Sparkman Dr, Huntsville, AL 35899 United States
AB: Using a 2.5-D code, we studied the propagation of inertial Alfven (IA) waves radiated from a localized oscillating source. Structure of the resonance cone in the fields, current, and density including nonlinear effects is investigated. Electron parallel drifts in the large current region generate secondary electrostatic waves affecting significant bulk heating as well as formation of elongated tail in the electron velocity distribution function. Alfven waves are known to transport energy from distant part of the outer space to near-Earth geo-space. The propagation of such waves over long distance and the microscopic mechanisms for their dissipation affecting plasma heating and acceleration in the auroral ionosphere remains one of the outstanding problems in space plasma physics. It is emerging now that such waves initiates from the distant sites of magnetic reconnections when current sheets thickness transverse to the magnetic field lines become small of the size of electron and ion skin depths. Low frequency perturbations in the current of such small transverse dimensions radiate inertial or kinetic Alfven waves. The radiated waves propagate over distances of several Earth radii in the mode of Alfven wave resonance cone dumping enrgy in the auiroral ionosphere. The entire problem of the generation, propagation and dissipation in the realistic configuration of the magnetosphere is a formidable task. In this paper we report results from our initial attempt to model the basic plasma processes driven in the course of the propagation of Alfven wave resonance cone emitted from a localized source. The currents in the resonance cone structure are seen to generate electrostatic waves in the frequency band of ion-acoustic and lower-hybrid waves, which heat the electrons. This provides an effective dissipation mechanism.
DE: 7807 Charged particle motion and acceleration
DE: 7839 Nonlinear phenomena
DE: 7843 Numerical simulation studies
DE: 7867 Wave/particle interactions
DE: 7899 General or miscellaneous
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly