1:45 PM - 2:00 PM
[PEM15-11] Gyrokinetic simulation of feedback instability in a dipole configuration
Keywords:aurora, magnetosphere-ionosphere coupling, Alfven wave, gyrokinetics
Feedback instability (FI) has been investigated as a possible mechanism explaining self-excitation of auroral arcs in the magnetosphere-ionosphere (M-I) coupling system. Nonlinear magnetohydrodynamic simulations of FI demonstrated growth of auroral structures, development of the Kelvin-Helmholtz instability, and turbulence transition both in slab and dipole field configurations. Recently, we also have carried out nonlinear gyrokinetic simulations of FI in the slab M-I coupling system which successfully confirm field-aligned acceleration of electrons by dispersive Alfven waves during auroral growth.
The present study reports recent extension of the gyrokinetic code GKV [1] to include M-I coupling in the dipole field configuration, where mirror motions of electrons and ions are fully considered. Results of the linear gyrokinetic simulation show growth of FI self-consistently including the parallel electric field and the mirror motions. Future extensions including the drift wave instabilities will also be discussed.
The present study reports recent extension of the gyrokinetic code GKV [1] to include M-I coupling in the dipole field configuration, where mirror motions of electrons and ions are fully considered. Results of the linear gyrokinetic simulation show growth of FI self-consistently including the parallel electric field and the mirror motions. Future extensions including the drift wave instabilities will also be discussed.