Propagation of Coronal Shocks in Fan-Like Magnetic Fields

Dusan Odstrcil

Abstract

 Recently, Klassen et al. (1999) analyzed two type II bursts observed on July 9, 1996 and they suggested that this event was caused by two shocks in different parts of the coronal loop structure. These shocks might be initiated by two separate sources or by a single source. In the second case, two shocks might result from a single disturbance due to different plasma parameters in different propagation directions. We study propagation of a shock in a fan-like magnetic field structure (2-D analogue of interacting coronal loops) by the two-dimensional numerical magnetohydrodynamic model. Explosion of a hot plasma in the coronal arcade model is investigated for various ratios of the mass density and magnetic field intensity in the loop-like coronal arcade structure. Ducting of shock waves occurs along such loops and significant separation of shock front parts is observed. The presented results support the idea that a single solar flare energy release can generate coronal disturbances observed as two separate type II radio bursts.

     Authors: D. Odstrcil and M. Karlicky

  Organization: Astronomical Institute
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