HR: 1340h
AN: SM53B-0408    [Abstracts]
TI: Simulation Study of Rapid Onset of Magnetic Reconnection
AU: Lapenta, G
EM: lapenta@lanl.gov
AF: LANL, MS: K717, Los Alamos, 87545 United States
AU: * Daughton, W
EM: daughton@lanl.gov
AF: University of Iowa, University of Iowa, Iowa City, 52242 United States
AU: Brackbill, J
EM: jub@lanl.gov
AF: Dartmouth College, Dartmouth College, Hanover, 03755
AU: Ricci, P
EM: paolo.ricci@dartmouth.edu
AF: Dartmouth College, Dartmouth College, Hanover, 03755
AB: The issue of reconnection onset remains a challenge to the plasma physics community. For most physical systems of interest, reconnection does not proceed in steady manner, but rather there are periods of time in which magnetic flux is accumulated, followed by other periods in which the energy is rapidly dissipated. In current sheet geometry, one of the most well-known onset mechanisms is the collisionless tearing instability. However, for systems such as the magnetotail, it appears the tearing instability is stabilized by the magnetic geometry. Furthermore, even if the tearing mode is unstable, fully kinetic 2D simulations indicate the instability saturates at small amplitude and does not generally trigger large-scale reconnection. Recent results from Los Alamos suggest a possible resolution to the onset problem by considering the role of current aligned plasma instabilities such as the lower-hybrid drift instability (LHDI). The nonlinear development of the LHDI leads to a variety of nonlinear modifications which can promote reconnection onset even in complex magnetic configurations such as the Earth's magnetotail. We report results of 2D and 3D kinetic simulations where the fast onset of reconnection in presence of current aligned modes is documented.
DE: 7827 Kinetic and MHD theory
DE: 7835 Magnetic reconnection
DE: 7843 Numerical simulation studies
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting