3-DIMENSIONAL SIMULATION STUDY OF THE MAGNETOHYDRODYNAMIC RELAXATION PROCESS IN THE SOLAR CORONA .1. SPONTANEOUS GENERATION OF TAYLOR-HEYVAERTS-PRIEST STATE

The magnetohydrodynamic (MHD) relaxation process in the solar coronal magnetic field is investigated in detail by using a three-dimensional MHD numerical simulation. The interaction between the magnetic loops w hich are located periodically above the photosphere is mainly consider ed. It is found that when each foot of the loops is twisted by the pho tospheric motion the loops aligned along the magnetic inversion line a re reconnected with each other. The magnetic reconnection process succ essively proceeds, and as a result a large-scale magnetic field parall el to the inversion line is spontaneously generated. The process is an MHD relaxation process where the magnetic configuration evolves towar d a linear force-free field as predicted by Taylor and by Heyvaerts & Priest. The Taylor-Heyvaerts-Priest hypothesis about the selective dis sipation of the energy compared to the magnetic helicity is numericall y verified. It is observed that a magnetic dip, which is a favorable e nvironment for the prominence condensation, is spontaneously generated through the relaxation process. Finally, the solar flare as a relaxat ion process of the magnetic energy is discussed, based on the simulati on results.