Distribution characteristics of coronal current density as indicator
for occurrence of solar flare
We investigated distribution characteristics of coronal current
density in an X-class flare-producing active region (AR12158; SOL2014-09-10) whose coronal magnetic structure and its temporal development were obtained by applying a nonlinear force-free model to a time-series of photospheric vector magnetic-field data. The temporal development of the structure showed how spatial distributions of coronal current density changed with time toward the onset of the flare. A fractal dimensional analysis of the spatial distributions revealed that a coronal current structure having fractal dimension was developed in the AR. Furthermore, we found that distribution
function of coronal current density was featured with a double power-law profile, and the value of current density at a breaking point of the profile
showed a noticeable time variation toward the onset of the flare. We presented a physical explanation of those distribution characteristics of coronal current
density, suggesting that they could be used as an indicator for the occurrence of a flare.
The coronal current structure was further investigated in this paper.
Reference
Kang, J. H., Magara, T., Inoue, S., Kubo, Y., & Nishizuka, N.
Publication of Astronomical Society of Japan, 68, 101
