DRIVING MECHANISM AND ONSET CONDITION OF A CONFINED ERUPTION
DRIVING MECHANISM AND ONSET CONDITION OF A CONFINED ERUPTION
复制标题
受限喷发的驱动机制和爆发条件
DOI：
10.1088/2041-8205/725/1/l38
复制
发表时间：
2010-12-10
影响因子：
7.9
通讯作者：
Wiegelmann, T.
中科院分区：
文献类型：
--
作者：
Guo, Y.;Ding, M. D.;Wiegelmann, T.
我们研究了2005年5月27日在太阳活动区（AR）NOAA 10767伴随着M1.1耀斑的一次局限喷发，其中在非线性无力场（NLFFF）外推中报告了爆发前的磁通量绳。观测结果显示，喷发结构有强烈的扭动运动，这表明确实存在磁绳，并在喷发过程中将其部分扭曲转化为扭动。使用NLFFF外推，我们计算的扭曲的爆发前的磁通绳，并发现它是非常好的协议与阈值的螺旋扭结不稳定性在数值模拟中发现。我们的结论是，通量绳的激活和上升是由不稳定性触发和驱动的。利用位场外推法，我们还估计了喷发前1小时AR中外部磁场衰减指数的高度分布。我们发现，衰减指数保持低于阈值的环面不稳定性的一个显着的高度范围以上的爆发通量绳。这提供了一个可能的解释喷发的局限性低日冕。
We study a confined eruption accompanied by an M1.1 flare in solar active region (AR) NOAA 10767 on 2005 May 27, where a pre-eruptive magnetic flux rope was reported in a nonlinear force-free field (NLFFF) extrapolation. The observations show a strong writhing motion of the erupting structure, suggesting that a flux rope was indeed present and converted some of its twist into writhe in the course of the eruption. Using the NLFFF extrapolation, we calculate the twist of the pre-eruptive flux rope and find that it is in very good agreement with thresholds of the helical kink instability found in numerical simulations. We conclude that the activation and rise of the flux rope were triggered and driven by the instability. Using a potential field extrapolation, we also estimate the height distribution of the decay index of the external magnetic field in the AR 1 hr prior to the eruption. We find that the decay index stays below the threshold for the torus instability for a significant height range above the erupting flux rope. This provides a possible explanation for the confinement of the eruption to the low corona.