Probing the Role of Magnetic-Field Variations in NOAA AR 8038 in Producing a Solar Flare and CME on 12 May 1997
Probing the Role of Magnetic-Field Variations in NOAA AR 8038 in Producing a Solar Flare and CME on 12 May 1997
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DOI：
10.1007/s11207-011-9793-7
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发表时间：
2011-07-01
期刊：
影响因子：
2.8
通讯作者：
Kiplinger, A. L.
中科院分区：
文献类型：
--
作者：
Jain, Rajmal;Awasthi, Arun K.;Kiplinger, A. L.
我们对1997年5月12日发生的日冕物质抛射（CME）和伴随的耀斑进行了多波长研究。我们提出了一个详细的调查磁场变化的NOAA活动区8038，这是在太阳上观察到的7 -aEuro千分之1997年5月16日。这个区域是安静的和衰减的，在它的磁盘通过期间只产生了一个非常小的耀斑活动。然而，在1997年5月12日，它产生了CME和相关的中等大小的1B/C1.3耀斑。H α滤波图和SOHO/MDI磁图的详细分析表明，连续但离散的浪涌活动，并在这个活跃的地区出现和取消通量。这些磁图的电影揭示了两个重要的结果，即在1997年5月13日10 -aEuro千分之10期间，先存区和新兴通量区的主要相反极性相互接近，以及移动磁特征（MMF）以大约10小时的准周期从主要北极喷出。这些活动可能是由光球会聚运动驱动的低层大气磁场重联引起的，这在磁图中很明显。对磁场变化（如磁通量、梯度和太阳黑子旋转）的定量测量显示，在这个活跃区域，自由能正在缓慢地储存在日冕中。缓慢的低层磁重联可能是负责在日冕中的磁自由能的存储和形成的S形核心领域或导致最终爆发的通量绳。极紫外线增亮的发生在S形核心领域之前的磁通绳的上升表明，喷发是由内部系绳切割重连，而不是外部突破重连触发。从前150秒H α带的快速分离中揭示的脉冲加速表明CME在内日冕中加速，这也与重联电场的时间分布一致。根据观测和分析，我们提出了一个定性模型，我们得出的结论是，质量喷射，暗条喷发，CME，以及随后的耀斑是相互关联的，应该被视为在太阳爆发的框架内。
We carried out a multi-wavelength study of a Coronal Mass Ejection (CME) and an associated flare, occurring on 12 May 1997. We present a detailed investigation of magnetic-field variations in NOAA Active Region 8038 which was observed on the Sun during 7 -aEuro parts per thousand 16 May 1997. This region was quiet and decaying and produced only a very small flare activity during its disk passage. However, on 12 May 1997 it produced a CME and associated medium-size 1B/C1.3 flare. Detailed analyses of H alpha filtergrams and SOHO/MDI magnetograms revealed continual but discrete surge activity, and emergence and cancellation of flux in this active region. The movie of these magnetograms revealed the two important results that the major opposite polarities of pre-existing region as well as in the emerging-flux region were approaching towards each other and moving magnetic features (MMF) were ejected from the major north polarity at a quasi-periodicity of about ten hours during 10 -aEuro parts per thousand 13 May 1997. These activities were probably caused by magnetic reconnection in the lower atmosphere driven by photospheric convergence motions, which were evident in magnetograms. The quantitative measurements of magnetic-field variations such as magnetic flux, gradient, and sunspot rotation revealed that in this active region, free energy was slowly being stored in the corona. Slow low-layer magnetic reconnection may be responsible for the storage of magnetic free energy in the corona and the formation of a sigmoidal core field or a flux rope leading to the eventual eruption. The occurrence of EUV brightenings in the sigmoidal core field prior to the rise of a flux rope suggests that the eruption was triggered by the inner tether-cutting reconnection, but not the external breakout reconnection. An impulsive acceleration, revealed from fast separation of the H alpha ribbons of the first 150 seconds, suggests that the CME accelerated in the inner corona, which is also consistent with the temporal profile of the reconnection electric field. Based on observations and analysis we propose a qualitative model, and we conclude that the mass ejections, filament eruption, CME, and subsequent flare were connected with one another and should be regarded within the framework of a solar eruption.