Applying the Weighted Horizontal Magnetic Gradient Method to a Simulated Flaring Active Region
Applying the Weighted Horizontal Magnetic Gradient Method to a Simulated Flaring Active Region
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DOI：
10.3847/1538-4357/aab891
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发表时间：
2018-04
期刊：
影响因子：
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通讯作者：
M. Korsós;P. Chatterjee;R. Erdélyi
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文献类型：
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作者：
M. Korsós;P. Chatterjee;R. Erdélyi
在这里，我们通过将加权水平磁梯度（WGM）应用于类太阳耀斑的磁流体动力学（MHD）模拟来测试由Korsós等人引入的耀斑前兆。在模拟的δ型太阳黑子中，研究了WGM在耀斑前的演化和不同高度的反极性太阳黑子的面积加权质心之间的距离参数的变化规律。这个太阳黑子发出了四个耀斑。我们找到了光球以上的最佳高度，在那里WGM方法的耀斑前体在每次耀斑之前都是可识别的。这些最佳高度与模拟中通过分析耀斑的热学和欧姆加热特征所确定的耀斑发生高度相当吻合。我们还根据每次耀斑爆发前极性相反的质心渐近渐远运动的持续时间，估计了耀斑爆发的预期时间。在相应的最佳高度上，每次耀斑的估计发生时间与实际发生时间吻合较好。该数值实验进一步支持了基于WGM方法的耀斑前兆的使用。
Here, we test the weighted horizontal magnetic gradient (WGM) as a flare precursor, introduced by Korsós et al., by applying it to a magnetohydrodynamic (MHD) simulation of solar-like flares. The preflare evolution of the WGM and the behavior of the distance parameter between the area-weighted barycenters of opposite-polarity sunspots at various heights is investigated in the simulated δ-type sunspot. Four flares emanated from this sunspot. We found the optimum heights above the photosphere where the flare precursors of the WGM method are identifiable prior to each flare. These optimum heights agree reasonably well with the heights of the occurrence of flares identified from the analysis of their thermal and ohmic heating signatures in the simulation. We also estimated the expected time of the flare onsets from the duration of the approaching–receding motion of the barycenters of opposite polarities before each single flare. The estimated onset time and the actual time of occurrence of each flare are in good agreement at the corresponding optimum heights. This numerical experiment further supports the use of flare precursors based on the WGM method.