HR: 08:30h
AN: SM51D-03    [Abstracts]
TI: Non-Equilibrium and Current Sheet Formation in Astronomical Magnetic Fields
AU: * Ng, C
EM: chung-sang.ng@unh.edu
AF: Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824 United States
AU: Bhattacharjee, A
EM: amitava.bhattacharjee@unh.edu
AF: Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824 United States
AB: For over three decades, E. N. Parker [Astrophys. J., 174, 499 (1972)] has argued that current sheets, or tangential discontinuities, of the magnetic field generally exist in magnetic equilibrium in astronomical magnetic fields, such as in stellar corona, and contribute to heating these plasmas to million degree temperatures, thus producing X-ray emission. We have recently presented a theorem [Phys. Plasmas, 5, 4028 (1998)] showing that the Parker model of coronal heating is rigorously viable. Our theorem proves that there can be at most one smooth magnetostatic equilibrium for a given smooth footpoint mapping between boundaries with line-tied magnetic fields. It follows that if such a static equilibrium is driven unstable by footpoint motions, there is no other smooth equilibrium for the plasma to relax to, leading to magnetic non-equilibrium and the formation of current sheets. New theoretical and numerical supports of this result will be presented. Possible topologies of such current sheets based on analytical considerations and numerical simulations will be discussed. Comparison will be made with methods of determining the locations of the current sheets (and thus possible sites of magnetic reconnection) based on theories of quasi-separatrix layers (QSLs).
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7835 Magnetic reconnection
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting