HR: 09:10h
AN: SH21A-05    [PDF]
TI: Flux Rope Acceleration and Enhanced Magnetic Reconnection
AU: Ren, Y
EM: yren@pppl.gov
AF: Princeton University, Princeton Plasma Physics Laboratory, Princeton, NJ 08543 United States
AU: * Cheng, C Z
EM: fcheng@pppl.gov
AF: Princeton University, Princeton Plasma Physics Laboratory, Princeton, NJ 08543 United States
AU: Choe, G S
EM: gchoe@pppl.gov
AF: Princeton University, Princeton Plasma Physics Laboratory, Princeton, NJ 08543 United States
AU: Qiu, J
EM: qiuj@plage.njit.edu
AF: New Jersey Institute of Technology, Center for Solar Research, Physics Department, Newark, NJ 07102 United States
AU: Moon, Y J
EM: yjmoon@kao.re.kr
AF: Korea Astronomy Observatory, Daejeon, Daejeon, 305-348 Korea, Republic of
AB: Recent flare and CME observations have shown that flux ropes are accelerated in the low corona in the form of coronal mass ejections or filament eruptions or soft X-ray plasma ejecta. The conclusion from these observations is that the most intense peak in the flare hard X-ray emissions and the maximum rate of increase in soft X-ray emission occur at the time of maximum acceleration of the flux rope's rising motion. To understand these observations we present results of our 2-1/2D MHD simulations of arcade field evolutions by employing a nonuniform anomalous resistivity. The simulation results 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 agreement with observations of the acceleration of flux ropes (CMEs) for several CME-flare events. For the X-class flare events the peak reconnection electric field is $\sim O(10^3 \, \rm V/m$) or larger, enough to accelerate electrons to over 100 keV in a field-aligned distance of 0.1 km and produce impulsive hard X-ray emission observed during the flare rise phase, consistent with the estimated reconnection rate obtained from the magnetogram data and two-ribbon emissions. Comparisons of the flux rope height, velocity and acceleration between our simulation results and observed CME-flare events will be presented.
DE: 7513 Coronal mass ejections
DE: 7519 Flares
DE: 7524 Magnetic fields
DE: 7529 Photosphere
DE: 7554 X rays, gamma rays, and neutrinos
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting