1 AU处ICME的一般3D形状的定量模型
Quantitative model for the generic 3D shape of ICMEs at 1 AU
摘要：
行星际成像仪提供行星际日冕物质抛射（ICME）的致密等离子体部分的2D投影视图，而原位测量提供沿航天器轨道的磁场和等离子体参数测量，因此沿1D切割。因此，这些数据只能提供其3D结构的部分视图。通过研究大量的ICMEs，在不同的距离从他们的顶点交叉，我们开发的统计方法，以获得一个定量的通用的三维形状的ICMEs。在第一种方法中，我们从理论上获得预期的统计分布的冲击正常的方向从假设简单的模型的三维冲击形状，包括扭曲的配置文件，并比较它们的兼容性与观察到的分布。在第二种方法中，我们使用冲击法线和磁通绳轴方向，以及碰撞参量，提供航天器轨迹的统计信息。不同的三维激波模型的研究表明，观测结果与围绕太阳顶点线对称的激波以及不对称到长宽比约为3的激波是相容的。此外，在其顶点附近的激波面是平的或倾斜的，这也是很少见的情况。其次，鞘层厚度和ICME速度沿ICME锋面没有全球趋势。最后，重新组合所有这些新的结果和我们以前的文章，我们提供了一个定量的ICME通用的3D形状，包括全球形状的冲击，鞘和通量绳。所获得的定量通用ICME形状将有几个目标的影响。例如，它限制了典型ICME数值模拟的输出。它也是深入研究ICME传播期间高能太阳和宇宙粒子传输以及模拟和预报近地空间天气条件的基础。
英文摘要：
Interplanetary imagers provide 2D projected views of the densest plasma parts of interplanetary coronal mass ejections (ICMEs) while in situ measurements provide magnetic field and plasma parameter measurements along the spacecraft trajectory, so along a 1D cut. As such, the data only give a partial view of their 3D structures. By studying a large number of ICMEs, crossed at different distances from their apex, we develop statistical methods to obtain a quantitative generic 3D shape of ICMEs. In a first approach we theoretically obtain the expected statistical distribution of the shock-normal orientation from assuming simple models of 3D shock shapes, including distorted profiles, and compare their compatibility with observed distributions. In a second approach we use the shock normal and the flux rope axis orientations, as well as the impact parameter, to provide statistical information across the spacecraft trajectory. The study of different 3D shock models shows that the observations are compatible with a shock symmetric around the Sun-apex line as well as with an asymmetry up to an aspect ratio around 3. Moreover, flat or dipped shock surfaces near their apex can only be rare cases. Next, the sheath thickness and the ICME velocity have no global trend along the ICME front. Finally, regrouping all these new results and the ones of our previous articles, we provide a quantitative ICME generic 3D shape, including the global shape of the shock, the sheath and the flux rope. The obtained quantitative generic ICME shape will have implications for several aims. For example, it constrains the output of typical ICME numerical simulations. It is also a base to develop deeper studies of the transport of high energy solar and cosmic particles during an ICME propagation, as well as for modeling and forecasting space weather conditions near Earth.
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。
