HR: 08:50h
AN: SH11C-04    [Abstracts]
TI: Resistive and Hall MHD Dynamics of a Flux Rope Model of Eruptive Flares: Simulations and Observations
AU: Ma, Z
EM: zhiwei-ma@uiowa.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03824
AU: * Bhattacharjee, A
EM: amitava.bhattacharjee@unh.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03824
AU: Forbes, T
EM: terry.forbes@unh.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03824
AB: During the last ten years, an eruptive flare model based on a loss of equilibrium in a coronal flux rope has been developed (Forbes and Priest 1995, Lin and Forbes 2000) and has been tested by observations from SOHO and RHESSI. We present fully self-consistent resistive and Hall MHD simulations of the model beginning from an equilibrium solution of the Grad-Shafranov equation in which a flux rope is nested in an arcade. The system is then driven by photospheric converging flows. It is found that the system evolves into a configuration with a thin current sheet which grows progressively thinner and longer, driving the flux rope upward. Magnetic reconnection in the thin current sheet eventually leads to the accelerated expulsion of the flux rope, as anticipated qualitatively by earlier theoretical calculations. In the resistive MHD model, the reconnection rate as well as the acceleration is controlled by the resistivity. In the Hall MHD model, the current sheet becomes thinner and more dynamic, the acceleration is faster and much more weakly dependent on the resistivity (at high values of the Lundquist number). Comparisons will be made with an eruptive event on 2003 November 18.
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005