高纬磁层顶位形统计分析

本文收集了1226个来自Cluster、Geotail、GOES、IMP8、Interball、LANL、Polar、TC1、THEMIS和Wind卫星磁层顶穿越事例，并主要利用时间推移使上游行星际磁场clock angle或等离子体变化特征与磁鞘中的相吻合方法为这些数据配对上来自ACE或Wind卫星5 min平均值太阳风数据.通过对这些数据以及网上公布的1482个Hawkeye卫星磁层顶穿越点数据分析研究，发现：（1）高纬磁层顶在极隙区存在内凹结构，其内凹范围比较大；（2）磁层顶内凹位置明显受地磁偶极倾角控制，最内凹点所对应的天顶角和地磁偶极倾角大致呈线性关系，这种关系在南北半球大致呈反对称；（3）磁层顶内凹深度、内凹范围以及内凹中心不变纬度基本不受地磁偶极倾角影响.

Statistical analysis of the high-latitude magnetopause location and shape

In this paper, we collect 1226 magnetopause crossings from Cluster, Geotail, GOES,IMP8, Interball, LANL, Polar, TCI, THEMIS and Wind. Their corresponding 5-minute average upstream solar wind parameters are determined from ACE or Wind mainly by shifting time to match the clock angle of the interplanetary magnetic field or the interplanetary plasma parameter variable profile with that of the magnetosheath. Based on the analysis of these crossings, along with 1482 Hawkeye magnetopause crossings from the website, it is concluded that: (1) the magnetopause is indented in the cup region with a large indented scope; (2) the location of the magnetopause indentation is controlled by the dipole tilt angle, which almost linearly influences the zenith angle of the magnetopause indentation vertex and whose influences on the north and the south magnetopause indentations are almost anti-symmetric;(3) the depth and the scope of the magnetopause indentation and the invariant latitude corresponding to the center of magnetopause indentation are almost not influenced by the dipole tilt angle.