講演情報

[PEM15-11]双極子磁場配位でのフィードバック不安定性のジャイロ運動論的シミュレーション

*渡邉 智彦1、藤田 慶二1 (1.名古屋大学大学院理学研究科)

キーワード:

オーロラ、磁気圏-電離圏結合、アルヴェン波、ジャイロ運動論

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.