HR: 14:45h
AN: SH53B-06    [Abstracts]
TI: Magnetic Flux Cancellation and Coronal Magnetic Energy
AU: * Welsch, B
EM: welsch@ssl.berkeley.edu
AF: Space Sciences Lab, UC Berkeley, 7 Gauss Way University of California, Berkeley, CA 94720-7450 United States
AB: I investigate the processes at work in the cancellation of normal magnetic flux in solar magnetograms, and study the relationships between cancellation and the budget of free energy in the coronal magnetic field that can power solar flares and CMEs. I begin by defining cancellation, and, focusing on reconnective cancellation, present the relevant equations describing the field evolution during cancellation. I then analyze these equations, to show that: 1) cancellation tends to reduce the magnetic energy of the hypothetical "open" field state; 2) in a sheared arcade field, steady cancellation adds free energy to the actual coronal field; and 3) horizontal magnetic flux can diffuse at a rate much lower than does the cancelling normal flux, even in the presence of constant resistivity. Finally, I briefly discuss the implications of boundary conditions in numerical simulations of flux cancellation.
DE: 7507 Chromosphere
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7529 Photosphere
DE: 7531 Prominence eruptions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly