The critical conditions for the onset of solar flares and coronal mass ejections
Abstract
Solar flares and coronal mass ejections (CMEs) are believed to be the explosive liberation of magnetic energy in the solar corona. However, the critical condition for their onset is not yet well understood, and thus the accurate prediction of their onset is still difficult. Which kind of instability determines the critical condition is a key question of this problem, because magnetohydrodynamic (MHD) instabilities, e.g., the kink and torus modes of instabilities, may cause the explosive energy liberation in the solar corona. Recently, Ishiguro and Kusano (2017) proposed that a new instability called double-arc instability (DAI) may work as the initial driver of solar flares and it can trigger the onset of the solar eruption by destabilizing the torus instability. In this paper, we analyze the spatiotemporal evolution of three-dimensional magnetic field structure which is reconstructed by the nonlinear force-free field (NLFFF) extrapolation technique for the solar active regions NOAA 11158 and 12673. The result suggests that the critical condition for the DAI well explains the onset of the major flares occurred in these active regions. Finally, we discuss the applicability of the critical condition to the prediction of flares and CMEs based on the statistical analysis of three hundred active regions.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E1887K