HR: 0830h
AN: SH51C-01    [Abstracts]
TI: A Mechanism for the Flux Cancellation Caused by Emerging Magnetic U-Loops in the Sun
AU: * Magara, T
EM: magara@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450 United States
AU: Antiochos, S K
AF: E. O. Hulburt Center for Space Research, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington DC, DC 20375 United States
AU: DeVore, C R
AF: Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington DC, DC 20375
AU: Linton, M G
AF: E. O. Hulburt Center for Space Research, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington DC, DC 20375 United States
AB: We used three-dimensional MHD simulation to study the evolution of U-shaped magnetic field lines (U-loops) in a flux cancellation region on the Sun. Emergence of U-loops is thought to be a process for causing flux cancellation at the solar surface, although the physical mechanism for this process is not obvious because the mass tends to accumulate at the dipped part of U-loops thereby reducing the buoyancy. Our flux emergence simulation reveals that a temporary siphon flow plays a key role in enhancing the buoyancy of the dipped part of U-loops and helps it emerge into the solar atmosphere against the gravity. By applying a model of emerging U-loops to an observed flux cancellation region, we study a possible configuration of magnetic field lines related to flux cancellation.
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7800 SPACE PLASMA PHYSICS
DE: 7843 Numerical simulation studies
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly