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arXiv 2106.07571astro-ph.SR
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研究揭示隐形日冕物质抛射的遥感技术

Investigating Remote-sensing Techniques to Reveal Stealth Coronal Mass Ejections

Erika Palmerio, Nariaki V. Nitta, Tamitha Mulligan, Marilena Mierla, Jennifer O'Kane, Ian G. Richardson, Suvadip Sinha, Nandita Srivastava, Stephanie L. Yardley, Andrei N. Zhukov

摘要:

太阳日冕物质抛射(CME)的爆发通常与一些可以在太阳盘图像中识别的特征有关。然而,也有一些情况下,日冕物质抛射数据中观察得很好的日冕物质抛射缺少一个清晰的低日冕对应物。这些事件在近年来受到关注,主要是由于多点观测的增加,现在被称为“隐形CME”。在这项工作中,我们分析了具有不同程度的模糊性隐形日冕物质抛射的例子。所有选定的案例研究产生了一个大规模的日冕物质抛射检测日冕仪,并从至少一个次要的观点,使先验知识的近似源区。对于每个事件,我们应用几种图像处理和几何技术,目的是评估这些方法是否可以提供额外的信息相比,“正常”的强度图像的研究。我们能够确定至少微弱的火山喷发的签名,所有事件的遥感数据进行仔细调查,注意到不同的处理图像可能需要适当的解释和分析难以捉摸的意见。我们还发现,几何技术的有效性强烈依赖于CME的传播方向相对于观察员和相对航天器的分离。在空间天气的背景下,能够观察并因此预测隐形CME是非常重要的,因为这种事件有时是所谓的“问题地磁风暴”的太阳对应物。

英文摘要:

Eruptions of coronal mass ejections (CMEs) from the Sun are usually associated with a number of signatures that can be identified in solar disc imagery. However, there are cases in which a CME that is well observed in coronagraph data is missing a clear low-coronal counterpart. These events have received attention during recent years, mainly as a result of the increased availability of multi-point observations, and are now known as 'stealth CMEs'. In this work, we analyse examples of stealth CMEs featuring various levels of ambiguity. All the selected case studies produced a large-scale CME detected by coronagraphs and were observed from at least one secondary viewpoint, enabling a priori knowledge of their approximate source region. To each event, we apply several image processing and geometric techniques with the aim to evaluate whether such methods can provide additional information compared to the study of "normal" intensity images. We are able to identify at least weak eruptive signatures for all events upon careful investigation of remote-sensing data, noting that differently processed images may be needed to properly interpret and analyse elusive observations. We also find that the effectiveness of geometric techniques strongly depends on the CME propagation direction with respect to the observers and the relative spacecraft separation. Being able to observe and therefore forecast stealth CMEs is of great importance in the context of space weather, since such events are occasionally the solar counterparts of so-called 'problem geomagnetic storms'.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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