HR: 09:40h
AN: SH21A-07    [PDF]
TI: Acceleration of Fast CME: A Parametric Study
AU: * Wu, S T
EM: wus@cspar.uah.edu
AF: The University of Alabama in Huntsville, Center for Space Plasma & Aeronomic Research, Olin B. King Technology Hall, Room S101, Huntsville, AL 35899 United States
AU: Zhang, T X
EM: zhangt@cspar.uah.edu
AF: The University of Alabama in Huntsville, Center for Space Plasma & Aeronomic Research, Olin B. King Technology Hall, Room S101, Huntsville, AL 35899 United States
AU: Tan, A
EM: atan@aamu.edu
AF: Alabama A \& M University, Department of Physics, Normal, AL 36762 United States
AB: The analysis of LASCO/SOHO, Skylab and Solar Maximum Mission (SMM) observations show that there are many CMEs initiated with streamer and flux-rope magnetic topology (Dere et al. 1999; St. Cyr et al., 1999; Plunkett et al., 2000). Two types of CMEs have been distinguished with different kinematic characteristics (MacQueen and Fisher, 1983; Andrews and Howard, 2001). These are fast CMEs with high initial speeds (i.e. constant speed) and slow CMEs with low initial speeds but gradual acceleration (i.e. accelerated CMEs). Efforts have been made to probe the underlying physics responsible for these dual characteristics. Low and Zhang (2002) proposed that fast and slow CMEs result from initial topology of the magnetic field characterized by normal and inverse quiescent prominences, respectively. Liu et al. have successfully performed a numerical MHD simulation for this scenario. In this presentation, we explore other possible processes using a 2.5D, time-dependent streamer and flux-rope MHD model (Wu and Guo, 1997) to investigate the dual kinematic properties of the CMEs by specifying the different initiation processes with a particular magnetic topology (i.e. inverse quiescent prominence magnetic topology). Two typical initiation processes are tested; (1) injection of the magnetic flux into the flux-rope causes additional Lorentz force to destabilize the streamer launching a CME (Wu et al., 1997) resulting in a category slow CME and (2) draining the plasma from the flux-rope together with flux injection leads to a balloon instability due to the magnetic buoyancy force which results in a impulsive eruption and launches a fast CME. References Andrews, M.D. and Howard, R.A., Space Sci. Rev., 95, 147, 2001 Dere, K.P. et al., Ap. J., 529, 575, 1999 Lin, et al., Proceedings of ICSC 2003: Solar Variability as an Input to the Earth's Environemnt, ESA-SP-535, 2003 (in press). Low, B.C. and Zhang, M., Ap. J., 564, L53, 2002. MacQueen, R.M. and Fisher, R.R., Solar Phys. 89, 89, 1983. Plunket, S., et al., Solar Phys. 194, 321, 2000. St. Cry., O.C. et al., J. Geophys. Res., 104, 12493, 1999. Wu, S.T. and Guo, W.P. in Coronal Mass Ejection, Geophys. Monogr. Ser. 99, (N. Crooker, et al. eds.), AGU Washington, DC 1997. Wu, S.T. et al., Solar Phys., 175, 719, 1997.
DE: 7509 Corona
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7531 Prominence eruptions
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting