HR: 10:30h
AN: SM32A-01 INVITED     [Abstracts]
TI: The "Newton Challenge": Properties of Forced Magnetic Reconnection
AU: * Pritchett, P L
EM: pritchet@physics.ucla.edu
AF: Department of Physics and Astronomy, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1547 United States
AB: Inspired by the observations of thin (ion-scale) current sheets at important magnetospheric boundaries, the study of the properties of thin current sheets has become very popular in recent years. Most of these investigations, however, have ignored the question of how the sheets are formed. Instead, usually a simple Harris-type current sheet is postulated at the outset, and the resulting behavior is then determined. Recently, a collaborative effort, dubbed the "Newton Challenge" and involving J. Birn, K. Galsgaard, M. Hesse, M. Hoshino, J. Huba, G. Lapenta, P.~L. Pritchett, K. Schindler, L. Yin, J. Büchner, T. Neukirch, and E.~R. Priest, was begun to investigate the transition from thicker to thin current sheets that can occur as a result of magnetopause deformations imposed by the solar wind. A standard 2-D model problem in which current sheet thinning was forced by imposing a finite deformation of the field above and below the current sheet was studied by a variety of physical models ranging from resistive MHD to fully kinetic particle models. The aim was to determine whether differences would arise between the fluid and kinetic treatments that might affect the onset of magnetic reconnection. The initial results indicate that full-particle, hybrid, and Hall-MHD models lead to fast reconnection and similar final states despite differences in energy transfer and dissipation. Resistive MHD simulations show reduced reconnection rates that depend on the magnitude of the resistivity. These results will be reviewed, and additional features of forced reconnection, including continuous forcing, open boundaries, the presence of a normal field component, and 3-D effects, will be discussed.
DE: 2744 Magnetotail
DE: 7835 Magnetic reconnection
DE: 7843 Numerical simulation studies
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly