Initiation and Early Kinematic Evolution of Solar Eruptions
Initiation and Early Kinematic Evolution of Solar Eruptions
复制标题
太阳喷发的起始和早期运动学演化
DOI：
10.3847/1538-4357/ab886a
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发表时间：
2020-05-01
影响因子：
4.9
通讯作者：
Ding, M. D.
中科院分区：
文献类型：
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作者：
Cheng, X.;Zhang, J.;Ding, M. D.
我们研究了12个太阳爆发的起源和早期演化，包括6个活动区热通道和6个静止的灯丝爆发，这是很好地观察到的太阳动力学天文台，以及由日地关系天文台后者。样本包括一次失败的喷发和11次日冕物质抛射，速度范围从493到2140 km s（-1）。详细的喷发运动学分析产生以下主要结果。(1)所有事件的早期演变包括一个缓慢的上升阶段，然后是一个主要的加速阶段，高度-时间曲线的显着不同，可以最好的拟合，分别由一个线性和指数函数。这表明不同的物理过程在这些阶段占主导地位，这与涉及单个过程的模型不同。(2)在两个阶段，爆发的运动学演化与耀斑光变曲线趋于同步。同步经常但并不总是紧密的。在大多数的暗条爆发（六分之五）中发现了脉冲耀斑阶段的延迟发生。这种延迟和它的趋势是更大的较慢的喷发有利于理想的MHD不稳定性模型。(3)在主加速的起始高度处的平均衰减指数接近两组事件的环面不稳定性的阈值（尽管它是基于热通道的暂定日冕场模型），这表明这种不稳定性启动并可能驱动主加速。
We investigate the initiation and early evolution of 12 solar eruptions, including six active-region hot channel and six quiescent filament eruptions, which were well observed by the Solar Dynamics Observatory, as well as by the Solar Terrestrial Relations Observatory for the latter. The sample includes one failed eruption and 11 coronal mass ejections, with velocities ranging from 493 to 2140 km s(-1). A detailed analysis of the eruption kinematics yields the following main results. (1) The early evolution of all events consists of a slow-rise phase followed by a main-acceleration phase, the height-time profiles of which differ markedly and can be best fit, respectively, by a linear and an exponential function. This indicates that different physical processes dominate in these phases, which is at variance with models that involve a single process. (2) The kinematic evolution of the eruptions tends to be synchronized with the flare light curve in both phases. The synchronization is often but not always close. A delayed onset of the impulsive flare phase is found in the majority of the filament eruptions (five out of six). This delay and its trend to be larger for slower eruptions favor ideal MHD instability models. (3) The average decay index at the onset heights of the main acceleration is close to the threshold of the torus instability for both groups of events (although, it is based on a tentative coronal field model for the hot channels), suggesting that this instability initiates and possibly drives the main acceleration.