HR: 1330h
AN: SH42B-0517    [PDF]
TI: Formation of Electric Current-Sheets and Magnetic Flux Ropes During Magnetic Flux Emergence
AU: * Zhang, M
EM: zhm@ucar.edu
AF: High Altitude Observatory / NCAR, PO Box 3000, Boulder, CO 80307 United States
AU: * Zhang, M
EM: zhm@ucar.edu
AF: National Astronomical Observatory, Chinese Academy of Sciences, Datun Road A20, Chaoyang District, Beijing, 100012 China
AU: Stone, J M
EM: jstone@astro.princeton.edu
AF: Department of Astrophysical Sciences and PACM, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 United States
AU: Low, B
EM: low@ucar.edu
AF: High Altitude Observatory / NCAR, PO Box 3000, Boulder, CO 80307 United States
AB: We present a numerical study of the formation of electric current sheets and magnetic flux ropes during emergence of flux into the solar corona. Using analytical initial states in which a new flux has emerged into a corona containing a preexisting flux system of the opposite polarity, we study the dynamical interaction between the two flux systems using the ZEUS MHD Codes. We find that the initially smooth interface between the opposite flux systems quickly steepens into a current sheet which immediately leads to magnetic reconnections and changes in magnetic topology. Magnetic flux ropes formed out of the reconnected fields. The ratio of the emerging flux to the preexisting flux is a discriminating physical factor. If this ratio is below some critical value, the flux rope produced will stay in some quiescent state in the atmosphere. If this ratio is sufficiently high, the flux rope produced will rise through the atmosphere and escape from the computational domain. These numerical results corroborate our recent theoretical studies which will be briefly summarized (Zhang and Low 2002, 2003, 2004).
DE: 7509 Corona
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7835 Magnetic reconnection
DE: 7843 Numerical simulation studies
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting