论文标题

从太阳能电晕底部到1 au的扭曲磁通绳的爆发和繁殖

Eruption and propagation of twisted flux ropes from the base of the solar corona to 1 au

论文作者

Regnault, F., Strugarek, A., Janvier, M., Auchère, F., Lugaz, N., Al-Haddad, N.

论文摘要

星际冠状质量弹出(ICME)源自我们恒星大气中发生的复杂磁结构的喷发。确定ICMES的一般特性和与太阳风相互作用的核心的物理过程是一项艰巨的任务,特别是仅使用一维的原位剖面。因此,这些现象仍然不太了解。在这项研究中,我们模拟了一组通量绳的传播,以了解在ICME传播过程中发生的某些物理过程,例如它们的生长或旋转。我们介绍了简化的太阳风中一组通量绳的传播的模拟。我们考虑在启动时考虑不同的磁场强度和尺寸,并表征了它们在传播过程中对通量绳索的特性的影响。我们在自适应网格精炼网格上使用冥王星代码的3D MHD模块。传播过程中通量绳的磁场的演变与从原位观测得出的进化定律相匹配。我们还模拟了航天器在地球上测量的原位曲线,我们与统计研究的结果进行了比较。我们发现在这些研究中获得的原位剖面与典型的曲线之间有很好的匹配。在它们的传播过程中,通量绳与风的磁场相互作用,但在用合成卫星交叉分析时,ICMES的现实特征仍然显示出逼真的特征。我们还表明,具有不同形状和方向的通量绳可能会导致类似的一维交叉。当使用一维交叉点提取ICME的磁性拓扑时,这需要注意。

Interplanetary Coronal Mass Ejections (ICMEs) originate from the eruption of complex magnetic structures occurring in our star's atmosphere. Determining the general properties of ICMEs and the physical processes at the heart of their interactions with the solar wind is a hard task, in particular using only unidimensional in situ profiles. Thus, these phenomena are still not well understood. In this study we simulate the propagation of a set of flux ropes in order to understand some of the physical processes occurring during the propagation of an ICME such as their growth or their rotation. We present simulations of the propagation of a set of flux ropes in a simplified solar wind. We consider different magnetic field strengths and sizes at the initiation of the eruption, and characterize their influence on the properties of the flux ropes during their propagation. We use the 3D MHD module of the PLUTO code on an Adaptive Mesh Refinement grid. The evolution of the magnetic field of the flux rope during the propagation matches evolution law deduced from in situ observations. We also simulate in situ profiles that spacecraft would have measured at the Earth, and we compare with the results of statistical studies. We find a good match between simulated in situ profiles and typical profiles obtained in these studies. During their propagation, flux ropes interact with the magnetic field of the wind but still show realistic signatures of ICMEs when analyzed with synthetic satellite crossings. We also show that flux ropes with different shapes and orientations can lead to similar unidimensional crossings. This warrants some care when extracting magnetic topology of ICMEs using unidimensional crossings.

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