Self-Exciting Driven Reconnection in a Solar Coronal
Magnetic Arcade with Reversed-Shear

Kanya Kusano

   The physical process in the impulsive onset of solar flares is not yet
well understood.
We recently proposed that the collapsing of magnetic arcade, which is
initiated by
the tearing mode instability growing on the magnetic shear inversion layer,
can
lead to the explosive growth of magnetic reconnection (Kusano et al. 2004).
The
mechanism of that can be explained as a process that magnetic reconnection
in the
tearing mode instability brings about another reconnection, which moreover
drives the
original reconnection. It is a self-exciting nonlinear process, in which the
driven reconnection
results from the spontaneous reconnection. The large-scale numerical
experiments are
performed to examine the validity of the model, using the parallelized
resistive magneto-
hydrodynamic code. The consistency of the simulation results with vector
magnetogram
observations in the several flare events is also discussed.