Evaluation of Applicability of a Flare Trigger Model based on Comparison of Geometric Structures

Abstract

The triggering mechanism(s) and critical condition(s) of solar flares are still not completely clarified, although various studies have attempted to elucidate them. We have also proposed a theoretical flare-trigger model based on MHD simulations Kusano et al. 2012, in which two types of small-scale bipole field, the so-called Opposite Polarity (OP) and Reversed Shear (RS) types of field, can trigger flares. In this study, we evaluated the applicability of our flare-trigger model to observation of 32 flares that were observed by the Solar Dynamics Observatory (SDO), by focusing on geometrical structures. We classified the events into six types, including the OP and RS types, based on photospheric magnetic field configuration, presence of precursor brightenings, and shape of the initial flare ribbons. As a result, we found that approximately 30% of the flares were consistent with our flare-trigger model, and the number of RS type triggered flares is larger than that of the OP type. We found none of the sampled events contradicts our flare model, although we cannot clearly determine the trigger mechanism of 70% of the flares in this study. We carefully investigated the applicability of our flare-trigger model and the possibility that other models can explain the other 70% of the events. Consequently, we concluded that our flare-trigger model has certainly proposed important conditions for flare-triggering.

arXiv comment19 pages, 4 figures, accepted by the Astrophysical Journal. Four animation files (Movie 1-4) that are corresponding to Figure 3 exist but it is not available here. Please see ApJ publication

References in corpus (32)

• A Model for Solar Coronal Mass Ejections
• Torus instability
• Confined and ejective eruptions of kink-unstable flux ropes
• The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: SHARPs -- Space-weather HMI Active Region Patches
• Ideal kink instability of a magnetic loop equilibrium
• Solar Flare Prediction Using SDO/HMI Vector Magnetic Field Data with a Machine-Learning Algorithm
• Structure, Stability, and Evolution of Magnetic Flux Ropes from the Perspective of Magnetic Twist
• Criteria for Flux Rope Eruption: Non Equilibrium versus Torus Instability
• Generalized Squashing Factors for Covariant Description of Magnetic Connectivity in the Solar Corona
• Magnetic Field Structures Triggering Solar Flares and Coronal Mass Ejections
• Photospheric flux cancellation and associated flux rope formation and eruption
• Magnetohydrodynamic Modeling of the Solar Eruption on 2010 April 8
• Critical decay index at the onset of solar eruptions
• High-resolution observations of flare precursors in the low solar atmosphere
• A Comparative Study of Confined and Eruptive Flares in NOAA AR 10720
• Catastrophe versus instability for the eruption of a toroidal solar magnetic flux rope
• The Relation between Solar Eruption Topologies and Observed Flare Features I: Flare Ribbons
• Solar Magnetic Feature Detection and Tracking for Space Weather Monitoring
• A Non-radial Eruption in a Quadrupolar Magnetic Configuration with a Coronal Null
• Study on Triggering Process of Solar Flares Based on Hinode/SOT Observations
• Helical Kink Instability in a Confined Solar Eruption
• Double arc instability in the solar corona
• Evidence for Solar Tether-cutting Magnetic Reconnection from Coronal Field Extrapolations
• Slip-Squashing Factors as a Measure of Three-Dimensional Magnetic Reconnection
• Evaluating (and Improving) Estimates of the Solar Radial Magnetic Field Component from Line-of-Sight Magnetograms
• Study on Precursor Activity of the X1.6 Flare in the Great AR 12192 with SDO, IRIS, and Hinode
• Observations and Modelling of the Pre-Flare Period of the 29 March 2014 X1 Flare
• Sunspot splitting triggering an eruptive flare
• Triggering Process of the X1.0 Three-ribbon Flare in the Great Active Region NOAA 12192
• Comparison between Hinode/SOT and SDO/HMI, AIA Data for the Study of the Solar Flare Trigger Process
• Supergranular-scale magnetic flux emergence beneath an unstable filament
• Breakout Reconnection Observed by the TESIS EUV Telescope

Cited by in corpus (5)

• Flare-productive active regions
• An MHD Modeling of Successive X2.2 and X9.3 Solar Flares of 2017 September 6
• Intrusion of Magnetic Peninsula toward the Neighboring Opposite-polarity Region That Triggers the Largest Solar Flare in Solar Cycle 24
• Multi-instrument Comparative Study of Temperature, Number Density, and Emission Measure during the Precursor Phase of a Solar Flare
• Resonant Axion-Photon Conversion in the Early Inspiral of Neutron Star Binaries