论文标题
爆发过程中CME通量绳的环形通量的演变
Evolution of the Toroidal Flux of CME Flux Ropes during Eruption
论文作者
论文摘要
冠状质量弹出（CME）是冠状磁场的大规模爆炸。据信，磁重新连接在喷发过程中显着建立了CME的核心结构，即磁通绳。然而，磁通绳的定量演变，尤其是其环形通量，尚不清楚。在本文中，我们研究了四个事件的CME通量绳的环形通量的演变。环形通量估计为通量绳的脚部区域中的磁通量，该磁通量通过一种同时考虑冠状色调和耀斑色带的钩子的方法来识别。我们发现，所有四个事件的CME通量绳的环形通量均显示出两相的演化：快速增加相位，然后降低相。我们进一步将环形通量的演变与地静止的操作环境卫星软X射线通量进行了比较，并发现它们基本上是同步的，只是前者的峰在某种程度上被延迟了。结果表明，CME通量绳的环形通量可能首先是由重新连接主要在剪切上覆盖的磁场中进行的，然后通过通量绳索内的扭曲磁场线之间的重新连接而降低，这是由于最近的3D 3D磁性磁性含量模拟CMES所启发的。
Coronal mass ejections (CMEs) are large-scale explosions of the coronal magnetic field. It is believed that magnetic reconnection significantly builds up the core structure of CMEs, a magnetic flux rope, during the eruption. However, the quantitative evolution of the flux rope, particularly its toroidal flux, is still unclear. In this paper, we study the evolution of the toroidal flux of the CME flux rope for four events. The toroidal flux is estimated as the magnetic flux in the footpoint region of the flux rope, which is identified by a method that simultaneously takes the coronal dimming and the hook of the flare ribbon into account. We find that the toroidal flux of the CME flux rope for all four events shows a two-phase evolution: a rapid increasing phase followed by a decreasing phase. We further compare the evolution of the toroidal flux with that of the Geostationary Operational Environmental Satellites soft X-ray flux and find that they are basically synchronous in time, except that the peak of the former is somewhat delayed. The results suggest that the toroidal flux of the CME flux rope may be first quickly built up by the reconnection mainly taking place in the sheared overlying field and then reduced by the reconnection among the twisted field lines within the flux rope, as enlightened by a recent 3D magnetohydrodynamic simulation of CMEs.
