Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations
Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations
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DOI：
10.1007/s11207-022-01974-x
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发表时间：
2022-03
期刊：
影响因子：
2.8
通讯作者：
P. Bhowmik;A. Yeates;O. Rice
中科院分区：
文献类型：
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作者：
P. Bhowmik;A. Yeates;O. Rice
日冕物质抛射（cme）是源自太阳的能量最大的事件之一，它会对日球层的磁性和微粒环境造成重大的突然破坏。因此，在目前的天基技术时代，对日冕物质抛射离开太阳的早期预警至关重要。当太阳爆发时，一些日冕物质抛射在太阳表面和日冕下显示出特征，从而使它们能够在到达近地卫星之前进行预测。然而，相当一部分日冕物质抛射没有这种可探测的特征，被称为“隐形日冕物质抛射”。旨在了解隐身日冕物质抛射背后的物理机制的理论和观测研究已经确定日冕流光是潜在的来源。在本文中，我们表明，即使在日冕磁场的准静态磁摩擦模型中，这种不涉及低日冕磁通量绳的喷发的流状喷涌爆发也是自然产生的。首先，我们证明磁摩擦可以以这种方式再现2008年6月1日至2日观测到的一个特殊的隐身CME事件。其次，我们表明，磁摩擦模型预测了重复喷发的发生，没有明显的低日冕信号，从这样的拱形，只要高，上覆磁力线被差速旋转充分剪切。二维参数研究表明，该喷发在参数变化下具有较强的鲁棒性，喷发频率主要由脚点剪切作用决定。这表明，磁摩擦模型在原则上可以提供隐秘喷发的早期迹象——甚至是提前爆发，无论它们是否源于低日冕通量绳的喷发。
Coronal mass ejections (CMEs) – among the most energetic events originating from the Sun – can cause significant and sudden disruption to the magnetic and particulate environment of the heliosphere. Thus, in the current era of space-based technologies, early warning that a CME has left the Sun is crucial. Some CMEs exhibit signatures at the solar surface and in the lower corona as the eruption occurs, thus enabling their prediction before arriving at near-Earth satellites. However, a significant fraction of CMEs exhibit no such detectable signatures and are known as “stealth CMEs”. Theoretical and observational studies aiming to understand the physical mechanism behind stealth CMEs have identified coronal streamers as potential sources. In this paper, we show that such streamer-blowout eruptions – which do not involve the lift-off of a low-coronal magnetic flux rope – are naturally produced even in the quasi-static magnetofrictional model for the coronal magnetic field. Firstly, we show that magnetofriction can reproduce in this way a particular stealth CME event observed during 1 – 2 June 2008. Secondly, we show that the magnetofrictional model predicts the occurrence of repeated eruptions without clear low-coronal signatures from such arcades, provided that the high, overlying magnetic field lines are sufficiently sheared by differential rotation. A two-dimensional parameter study shows that such eruptions are robust under variation of the parameters, and that the eruption frequency is primarily determined by the footpoint shearing. This suggests that magnetofrictional models could, in principle, provide early indication – even pre-onset – of stealth eruptions, whether or not they originate from the eruption of a low-coronal flux rope.