HR: 1330h
AN: SH22A-0178    [PDF]
TI: Eruption of a Buoyantly Emerging Magnetic Flux Rope
AU: * Manchester, W B
EM: chipm@umich.edu
AF: University Of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 United States
AU: Fan, Y
EM: yfan@hao.ucar.edu
AF: High Altitude Observatory, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Gombosi, T
EM: tamas@umich.edu
AF: University Of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 United States
AU: De Zeeuw, D
EM: darrens@umich.edu
AF: University Of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 United States
AU: Sokolov, I
EM: igorsok@umich.edu
AF: University Of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 United States
AU: Toth, G
EM: gtoth@hermes.elte.hu
AF: Eotvos University, Pazmany setany 1/A, Budapest, 1117 Hungary
AB: We present a three-dimensional numerical ideal magnetohydrodynamic simulation designed to model the emergence of magnetic flux passing from below the photosphere into the corona. For the initial state, we prescribe a plane parallel atmosphere that comprises the convection zone, isothermal photosphere and chromosphere, and isothermal corona. Embedded in this system is a isolated horizontal magnetic flux rope located 10 photospheric pressure scale heights below the photosphere. The flux rope is uniformly twisted with plasma temperature inside the tube reduced to compensate for the magnetic pressure. Density is reduced in the middle of the rope so that this section buoyantly rises. The early evolution of precedes with the middle of the rope rising to the photosphere and expanding into the corona. Just as it seems the system might approach equilibrium, the upper part of the flux rope begins to separate from the lower, mass ladened part. The separation occurs by stretching of the field to form a current sheet where reconnection severs the field lines to form a new system of closed flux. This flux then erupts into the corona. Essential to the eruption process are shearing motions driven by the Lorentz force which naturally occurs as the rope expands in the pressure stratified atmosphere. The shearing motions transport axial flux and energy to the expanding portion of the magnetic field which contributes to the eruption. Once the axial flux is largely transported from the submerged field, the expansion of the magnetic field in the corona begins to decelerate.
DE: 7509 Corona
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7531 Prominence eruptions
DE: 7843 Numerical simulation studies
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting