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). The coronal magnetic structure of this AR and its temporal development were obtained by applying a nonlinear force-free field model to a time-series data of photospheric vector magnetic field observed by SDO. The temporal development showed how spatial distributions of coronal current density changed with time toward the onset of the flare. Applying a fractal dimensional analysis to the spatial distributions revealed that a coronal current structure having fractal spatiality 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 distribution characteristics of coronal current
density, suggesting that the characteristics could be used as an indicator for the occurrence of a flare.
The coronal current structure responsible for producing a flare 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
