HR: 1340h
AN: SM43C-1239    [Abstracts]
TI: Magnetic reconnection induced by the MHD-scale Kelvin-Helmholtz instability in the non-linear stage; Two-fluid simulations including finite electron inertia
AU: * Nakamura, T
EM: takuma@geo.titech.ac.jp
AF: Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551 Japan
AU: Fujimoto, M
EM: fujimoto@geo.titech.ac.jp
AF: Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551 Japan
AU: Otto, A
EM: ao@how.gi.alaska.edu
AF: University of Alaska, Fairbanks, Univ Alaska Fairbanks Geophysical Inst 903 Koyukuk Inst, Fairbanks, AK 99775-7320 United States
AB: We have performed two-fluid simulations including finite electron inertial effects to investigate the structure of an MHD-scale Kelvin-Helmholtz (KH) vortex. In understanding the structure of an MHD-scale KH vortex, magnetic reconnection induced by the flow of KH vortex should not be neglected. We have showed by two-dimensional two-fluid simulations in various fundamental magnetic configurations that magnetic reconnection in the vortex flow crucially changes the structure of the KH vortex. In this study, we concentrate particularly on the cases in which in-the-plane magnetic configuration is anti-parallel across the shear layer (the anti-parallel case). In this case, a KH vortex does not need to highly roll-up for the onset of magnetic reconnection. Moreover, such a reconnection process assists the vortex to grow to a highly rolled-up state even when in-the-plane magnetic field too strong for the KH instability to achieve this stage by itself. We will also show by three-dimensional simulations that the KH mode having the wavevector that will involve reconnection (magnetic field projected onto the wavevector direction having different signs across the shear layer) often dominates in a realistic magnetic geometry. These results presented here imply that magnetic reconnection in the flow of a KH instability takes place rather easily and plays an important role in space plasma dynamics involving a shear flow and a current layer. We will present detailed analyses that reveal the nature of these surprising results.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2724 Magnetopause and boundary layers
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005