Distribution characteristics of coronal electric current density as an indicator for the occurrence of a solar flare

作者：Kang Jihye; Magara Tetsuya^*; Inoue Satoshi; Kubo Yuki; Nishizuka Naoto

来源：Publications of the Astronomical Society of Japan, 2016, 68(6): 101.

DOI：10.1093/pasj/psw092

• magnetohydrodynamics (MHD)
• methods: numerical
• Sun: activity
• Sun: corona
• Sun: magnetic fields

In this paper we investigate the distribution characteristics of the coronal electric current density in a flare-producing active region (AR12158; SOL2014-09-10) by reconstructing nonlinear force-free (NLFF) fields from photospheric magnetic field data. A time series of NLFF fields shows the spatial distribution and its temporal development of coronal current density in this active region. A fractal dimensional analysis shows that a concentrated coronal current forms a structure of fractal spatiality. Furthermore, the distribution function of coronal current density is featured with a double power-law profile, and the value of electric current density at the breaking point of a double power-law fitting function shows a noticeable time variation toward the onset of an X-class flare. We discuss that this quantity will be a useful indicator for the occurrence of a flare.

• 出版日期2016-12