34th Solar Physics Division Meeting, June 2003
Session 16 Flares and Microflares II
Poster, Wednesday, June 18, 2003, 3:30-5:00pm, Mezzanine

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[16.08] Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate

C. Z. Cheng, G. S. Choe, Y. Ren (Princeton Plasma Physics Laboratory), Y.-J. Moon (BBSO/NJIT and Korea Astronomy Observatory, Korea)

A physical mechanism of flares, in particular for the flare rise phase, has emerged from our 2-1/2D resistive MHD simulations. The dynamical evolution of current sheet formation and magnetic reconnection and flux rope acceleration subject to continuous, slow increase of magnetic shear in the arcade are studied by employing a non-uniform anomalous resistivity in the reconnecting current sheet under gravity. The simulation results directly relate the flux rope's accelerated rising motion with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. The simulation results provide good quantitative agreements with observations of the acceleration of flux rope, which manifests in the form of SXR ejecta or erupting filament or CMEs, in the low corona. Moreover, we have examined several X-class flare events and the peak reconnection electric field is found to be ~ O(102 V/m) or larger, enough to accelerate particles to over 100 keV in a field-aligned distance of 10 km. Nonthermal electrons thus generated can produce hard X-rays, consistent with impulsive HXR emission observed during the flare rise phase.

This work was supported by the DoE Contract No. DE-AC02-76-CHO3073 at PPPL.


The author(s) of this abstract have provided an email address for comments about the abstract: fcheng@pppl.gov

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