Triggering Process of the X1.0 Three-ribbon Flare in the Great Active Region NOAA 12192

Journal Article · Sat Apr 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA6682· OSTI ID:22661187

Bamba, Yumi ^[1]; Inoue, Satoshi; Kusano, Kanya; Shiota, Daikou ^[2]

---

1. Institute of Space and Astronautical Science (ISAS)/Japan Aerospace Exploration Agency (JAXA) 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)
2. Institute for Space-Earth Environmental Research (ISEE)/Nagoya University Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)

The solar magnetic field in a flare-producing active region (AR) is much more complicated than theoretical models, which assume a very simple magnetic field structure. The X1.0 flare, which occurred in AR 12192 on 2014 October 25, showed a complicated three-ribbon structure. To clarify the trigger process of the flare and to evaluate the applicability of a simple theoretical model, we analyzed the data from Hinode /Solar Optical Telescope and the Solar Dynamics Observatory /Helioseismic and Magnetic Imager, Atmospheric Imaging Assembly. We investigated the spatio-temporal correlation between the magnetic field structures, especially the non-potentiality of the horizontal field, and the bright structures in the solar atmosphere. As a result, we determined that the western side of the positive polarity, which is intruding on a negative polarity region, is the location where the flare was triggered. This is due to the fact that the sign of the magnetic shear in that region was opposite that of the major shear of the AR, and the significant brightenings were observed over the polarity inversion line (PIL) in that region before flare onset. These features are consistent with the recently proposed flare-trigger model that suggests that small reversed shear (RS) magnetic disturbances can trigger solar flares. Moreover, we found that the RS field was located slightly off the flaring PIL, contrary to the theoretical prediction. We discuss the possibility of an extension of the RS model based on an extra numerical simulation. Our result suggests that the RS field has a certain flexibility for displacement from a highly sheared PIL, and that the RS field triggers more flares than we expected.

• OSTI ID: 22661187
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 838; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPUTERIZED SIMULATION
CORRELATIONS
DISTURBANCES
FLARING
FLEXIBILITY
FORECASTING
MAGNETIC FIELDS
REVERSED SHEAR
SOLAR ATMOSPHERE
SOLAR FLARES
SUN
SUNSPOTS
TELESCOPES