The contraction of flare loops and its impact on the solar lower atmosphere

Abstract

This short reviewing article is intended to introduce a possibly existing relevance for three important macroscopic behaviors of solar flares. The behaviors include the contraction of flare loops (implosion), the rapid change of magnetic fields and seismic waves during flares. We show that the phenomena basically reflects a process of rapid restructuring of sheared magnetic field by a release of free magnetic energy. The contraction and rapid magnetic changes might be the direct consequences of the restructuring. Also the flattening of magnetic loops caused by the contraction in the corona will impart momentum down to the photosphere even to the solar interior. Part of the energy transported by the downward momentum can account for seismic waves. All phenomena, putting together, show that the magnetic reconnection process during the early impulsive phase is quite different from during the gradual phase and plays a dominant role in powering solar flares.