Magnetic Field Re-configuration Associated With a Slow Rise Eruptive X1.2 Flare in NOAA Active Region 11944
Magnetic Field Re-configuration Associated With a Slow Rise Eruptive X1.2 Flare in NOAA Active Region 11944
复制标题
DOI：
10.3389/fspas.2022.816523
复制
发表时间：
2022-04
期刊：
影响因子：
--
通讯作者：
V. Yurchyshyn;Xu Yang;G. Nita;G. Fleishman;V. Abramenko;S. Inoue;E. Lim;W. Cao
中科院分区：
文献类型：
--
作者：
V. Yurchyshyn;Xu Yang;G. Nita;G. Fleishman;V. Abramenko;S. Inoue;E. Lim;W. Cao
利用多波长观测，我们分析了2014年1月7日在靠近圆盘中心的活跃区（AR） NOAA 11944爆发的X1.2级逐渐耀斑的磁场变化。在耀斑之后观测到一个快速的日冕物质抛射（CME），它明显地向西南方向偏转。在耀斑之前和之后的喷发地点观察到色球灯丝。我们利用SDO/HMI数据对AR上方的日冕磁场进行了非线性无力场外推，并研究了喷发前AR磁场的演变。外推的数据使我们能够在事件发生前几小时检测到喷发地点出现的几条磁通量绳的特征。喷发地点位于倾斜的太阳黑子场下，衰变指数在1.0 ~ 1.5之间变化。这可能导致爆发场沿着倾斜的磁边界滑动，而不是垂直爆发，从而解释了耀斑的缓慢上升以及观测到的CME的方向。我们使用符号奇点工具来量化模型扭曲的演化变化和观测到的当前螺旋度数据，并发现在事件发生之前和事件发生后，这两个数据集中当前系统的快速和协调变化。
Using multi-wavelength observations, we analysed magnetic field variations associated with a gradual X1.2 flare that erupted on January 7, 2014 in active region (AR) NOAA 11944 located near the disk center. A fast coronal mass ejection (CME) was observed following the flare, which was noticeably deflected in the south-west direction. A chromospheric filament was observed at the eruption site prior to and after the flare. We used SDO/HMI data to perform non-linear force-free field extrapolation of coronal magnetic fields above the AR and to study the evolution of AR magnetic fields prior to the eruption. The extrapolated data allowed us to detect signatures of several magnetic flux ropes present at the eruption site several hours before the event. The eruption site was located under slanted sunspot fields with a varying decay index of 1.0-1.5. That might have caused the erupting fields to slide along this slanted magnetic boundary rather than vertically erupt, thus explaining the slow rise of the flare as well as the observed direction of the resulting CME. We employed sign-singularity tools to quantify the evolutionary changes in the model twist and observed current helicity data, and found rapid and coordinated variations of current systems in both data sets prior to the event as well as their rapid exhaustion after the event onset.