论文标题

确定CME取向及其传播的后果

Determination of CME orientation and consequences for their propagation

论文作者

Martinic, Karmen, Dumbovic, Mateja, Temmer, Manula, Veronig, Astrid, Vršnak, Bojan

论文摘要

行星际磁场的构型和相关环境太阳风在黄道和子午平面中的配置不同。因此,人们可以期望冠状质量弹出(CME)的通量轴轴的方向会影响CME本身的传播。但是,CME取向的确定,尤其是图像数据,仍然是一项具有挑战性的任务。这项研究旨在提及近调环境中不同CME取向测定方法。同样,它旨在研究行星际CME(ICME)的鞘区域中的非辐射流,以提供第一个将ICME方向与其传播相关联的代理。我们研究了2008 - 2015年期间22个孤立的CME-ICME事件。我们使用以下内容确定了近似环境中的CME方向:1)CME的3D重建,其刻度圆柱形壳(GCS)模型应用于立体声和SOHO任务提供的可粘瘤图像,并; 2)应用于SOHO/LASCO C2和C3 CORONAGRAPHS的单个航天器数据的椭圆拟合。在近地环境中,我们使用原位等离子体和田间数据获得了相应的ICME的方向,并研究了其鞘区域中的非辐射流(NRF)。发现GCS和椭圆形拟合确定CME取向的能力仅限于可靠地区分事件的高或低倾斜度。发现大多数正在研究的CME-ICME对的特征是低倾斜度。对于大多数CME-ICME对,我们从远程和原位数据中获得对倾斜度的一致估计。在鞘区域中观察到的NRF显示出更大的Y方向与Z方向流量比,这表明CME方向可能会对CME传播产生影响。

The configuration of the interplanetary magnetic field and features of the related ambient solar wind in the ecliptic and meridional plane are different. Therefore, one can expect that the orientation of the flux-rope axis of a coronal mass ejection (CME) influences the propagation of the CME itself. However, the determination of the CME orientation, especially from image data, remains a challenging task to perform. This study aims to provide a reference to different CME orientation determination methods in the near-Sun environment. Also, it aims to investigate the non-radial flow in the sheath region of the interplanetary CME (ICME) in order to provide the first proxy to relate the ICME orientation with its propagation. We investigated 22 isolated CME-ICME events in the period 2008-2015. We determined the CME orientation in the near-Sun environment using the following: 1) a 3D reconstruction of the CME with the graduated cylindrical shell (GCS) model applied to coronagraphic images provided by the STEREO and SOHO missions and; 2) an ellipse fitting applied to single spacecraft data from SOHO/LASCO C2 and C3 coronagraphs. In the near-Earth environment, we obtained the orientation of the corresponding ICME using in situ plasma and field data and also investigated the non-radial flow (NRF) in its sheath region. The ability of GCS and ellipse fitting to determine the CME orientation is found to be limited to reliably distinguish only between the high or low inclination of the events. Most of the CME-ICME pairs under investigation were found to be characterized by a low inclination. For the majority of CME-ICME pairs, we obtain consistent estimations of the tilt from remote and in situ data. The observed NRFs in the sheath region show a greater y direction to z direction flow ratio for high-inclination events, indicating that the CME orientation could have an impact on the CME propagation.

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