Eruptivity in Solar Flares: The Challenges of Magnetic Flux Ropes
Eruptivity in Solar Flares: The Challenges of Magnetic Flux Ropes
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DOI：
10.3847/1538-4357/abf3c1
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
P. Lin;K. Kusano;K. Leka
中科院分区：
文献类型：
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作者：
P. Lin;K. Kusano;K. Leka
为了分析太阳耀斑的爆发和受限性质，提出了两种新的识别喷发场线的方案，即r方案和q方案，作为Lin等人提出的原始rm方案的扩展。受来自NOAA活动区12192的三个太阳耀斑被rm错误分类的激励，我们引入了对r方案的改进，采用“磁扭转通量”来近似作用在磁通量绳上的力平衡；在q方案中，重联场由锚定在耀斑带上的那些场线表示。根据太阳动力学观测站/日震和磁成像仪获得的数据，利用非线性无力场外推模型，建立了来自29个不同活动区的51个M5.0级以上耀斑的日冕磁场。然后进行了基于线性判别函数分析的统计分析，结果表明，尽管两种方案都对51个耀斑进行了中等成功的分类，但只有Q方案可以改进三个目标事件的日冕物质抛射-喷发分类。我们发现，高度扭曲的场线和耀斑带场线具有相等的平均无力常数α，但所有与耀斑带相关的场线的长度都小于150 mm。这些发现使我们得出结论，使用任何基于普通磁无势测量的量来区分MFR和环境磁场是具有挑战性的。
Two new schemes for identifying field lines involved in eruptions, the r-scheme and q-scheme, are proposed to analyze the eruptive and confined nature of solar flares, as extensions to the original r m scheme proposed in Lin et al. Motivated by three solar flares originating from NOAA Active Region 12192 that are misclassified by r m , we introduce refinements to the r-scheme employing the “magnetic twist flux” to approximate the force balance acting on a magnetic flux rope (MFR); in the q-scheme, the reconnected field is represented by those field lines that anchor in the flare ribbons. Based on data obtained by the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the coronal magnetic field for 51 flares larger than M5.0 class, from 29 distinct active regions, is constructed using a nonlinear force-free field extrapolation model. Statistical analysis based on linear discriminant function analysis is then performed, revealing that despite both schemes providing moderately successful classifications for the 51 flares, the coronal mass ejection-eruptivity classification for the three target events can only be improved with the q-scheme. We find that the highly twisted field lines and the flare-ribbon field lines have equal average force-free constant α, but all of the flare-ribbon-related field lines are shorter than 150 Mm in length. The findings lead us to conclude that it is challenging to distinguish the MFR from the ambient magnetic field using any quantity based on common magnetic nonpotentiality measures.