HR: 1340h
AN: SH44A-1726    [Abstracts]
TI: Explosive Instability and Coronal Heating
AU: * Dahlburg, R B
EM: rdahlbur@lcp.nrl.navy.mil
AF: LCP&FD, Naval Research Laboratory, Washington, DC 20375,
AU: Liu, J
AF: LCP&FD, Naval Research Laboratory, Washington, DC 20375,
AU: Liu, J
AF: Space Science Division, Naval Research Laboratory, Washington, DC 20375,
AU: Klimchuk, J A
AF: Space Science Division, Naval Research Laboratory, Washington, DC 20375,
AU: Nigro, G
AF: Space Science Division, Naval Research Laboratory, Washington, DC 20375,
AB: The observed energy loss rate from the solar corona implies that the coronal magnetic field has a critical angle at which energy is released. It has been hypothesized that at this critical angle an "explosive instability" would occur, leading to an enhanced conversion of magnetic energy into heat. In earlier investigations we have shown that a shear-dependent process called "secondary instability" could account for many of the distinctive features of the hypothetical "explosive instability." Here we show that this "secondary instability" can occur in a system with line-tied magnetic fields and boundary shearing. We also show that, as the disturbance due to secondary instability attains finite amplitude, there is a transition to turbulence which leads to enhanced dissipation of magnetic and kinetic energy. Furthermore, after each dissipative burst, the system is able to reform itself so that a subsequent burst can occur. These results are obtained from numerical simulations performed with a new parallelized, viscoresistive, three-dimensional code that solves the cold plasma equations. The code employs a Fourier collocation -- finite difference spatial discretization, and uses a third-order Runge-Kutta temporal discretization.
DE: 7509 Corona
DE: 7526 Magnetic reconnection (2723, 7835)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting