HR: 0800h
AN: SM51A-04    [Abstracts]
TI: Reconnection Onset in the Magnetotail: Kinetic Theory and Particle Simulations
AU: * Sitnov, M I
EM: sitnov@umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742-3511, United States
AU: Divin, A V
EM: andrey.div@gmail.com
AF: St. Petersburg University, Universitetskaya nab., 7-9, St. Petersburg, Russian Federation
AU: Swisdak, M M
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742-3511, United States
AU: Guzdar, P N
EM: guzdar@glue.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742-3511, United States
AU: Drake, J F
EM: drake@plasma.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742-3511, United States
AB: The mechanism of the onset of magnetic reconnection in collisionless plasmas in the tails of planetary magnetospheres and similar processes in the solar corona is one of the most fundamental and yet not fully solved problems of space plasma physics. Nonlocal kinetic linear stability analysis of the tearing mode, which is responsible for the onset of spontaneous reconnection, reveals the key role of passing electrons in the mode destabilization. However, the linear theory taking into account passing electrons is cumbersome and difficult to independently verify. Also, it does not preclude the nonlinear destabilization of the tearing mode before it reaches amplitudes sufficient to change the initial tail topology of magnetic field lines and form X-lines. Therefore, the destabilization mechanism must be verified by particle simulations. Modeling the onset with particle codes requires either extremely large simulation boxes or open boundary conditions. We show that in a simulation setup with open boundaries bursts of spontaneous reconnection are detected in the outflow regions of the initial X-point geometry. These bursts strongly resemble the ion tearing instability predicted by Schindler [1974] as a mechanism for magnetospheric substorms in the tail of Earth's magnetosphere. Quenching the onset by replacing open boundary conditions for particles with their reintroduction reveals the key role of passing particles in the tearing destabilization. The theory and simulations are consistent with Geotail statistics on the size of plasmoids and their origin in the tail. They have important implications for Cluster and THEMIS observations.
DE: 2744 Magnetotail
DE: 2772 Plasma waves and instabilities (2471)
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7833 Mathematical and numerical techniques (0500, 3200)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly