HR: 0800h
AN: SH51B-1209    [Abstracts]
TI: Nonlinear relations among wave frequencies and phases in parametric instabilities of Alfven waves
AU: * Nariyuki, Y
EM: nariyuki@essst.kyushu-u.ac.jp
AU: Hada, T
EM: hada@esst.kyushu-u.ac.jp
AB: In various areas in space plasma, for instance in the solar wind and in the foreshock region of planetary bowshocks, parametric instabilities are thought to play essential roles in generating magnetohydrodynamic turbulence. In this presentation we discuss relations among frequencies and phases in various parametric instabilities of circularly polarized Alfven waves, within the context of one dimensional Hall MHD system. Linear perturbation analysis and numerical simulation are used to find characteristics of parametric decay and modulational instabilities. We show that some essential physical processes can be argued by examining difference equations for the wave phases. Furthermore, based on the results obtained in the present analysis, we propose ways to improve techniques for identifying nonlinear coupling among waves such as the bi-coherence analysis.
DE: 7811 Discontinuities (2109)
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7863 Turbulence (4490)
DE: 7868 Wave/wave interactions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005