应用GNSS TEC技术观测行星际激波对等离子体层的压缩  

Using GNSS TEC technique to observe compression of the plasmasphere by an interplanetary shock

作　　者：郝永强[1] 李泉翰 张东和[1] 肖佐[1] 杨光林[2] 黄聪 HAO YongQiang;LI QuanHan;ZHANG DongHe;XIAO Zuo;YANG GuangLin;HUANG Cong(School of Earth and Space Sciences,Peking University,Beijing 100871,China;National Center for Space Weather,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国气象局国家空间天气监测预警中心,北京100081

出　　处：《中国科学：技术科学》2018年第8期853-862,共10页Scientia Sinica(Technologica)

基　　金：国家自然科学基金项目(批准号:41574144);中国科学院空间科学战略性先导科技专项(编号:XDA15052400)资助

摘　　要：2015年3月17日一个强太阳风激波到达地球,同时地面GPS接收机网络观测到TEC的突然变化,在Hao等人(2017)的工作中把TEC变化初步归因于激波对向阳面磁层的压缩,本文进一步分析北斗接收机和更高时间分辨率的GPS接收机的观测,并推断等离子体沿垂直地磁场磁力线的方向朝向地球运动,会在低纬赤道面附近形成一个等离子体汇聚的区域,所有穿过该区域的GPS和北斗卫星信号都会观测到TEC的变化.此外,本文考察了多个LEO卫星上搭载的GPS接收机观测,没有发现相关的TEC扰动,原因可能是事件发生的瞬间LEO卫星没有处于最佳的观测位置.通过考察上述多种观测数据,我们认为GNSS TEC技术可用于对激波压缩磁层过程的遥感观测,未来有望成为卫星实地探测技术的有效补充.An interplanetary shock impinged on the Earth＇s magnetosphere on 17 March 2015, and caused instant change of total electron content（TEC） measured by ground-based global positioning system（GPS） receivers. Hao et al.（2017） attributed the sudden TEC variation to magnetospheric compression by the shock, and in this paper we follow to examine the process by incorporating high timeresolution（1 s） TEC data from some GPS receivers as well as TEC measurements from Bei Dou Navigation Satellite System. These observations add new understandings to the reaction of magnetosphere to a strong shock. The compression drives plasma in dayside magnetosphere to move earthward, and the contraction of the Earth＇s magnetic field will make plasma concentrate near the equatorial plane. The scenario involves dynamics of the plasmasphere where the plasma is dense enough to contribute to the variations of both GPS and Beidou TEC. In addition, we also inspect TEC measured onboard several low Earth orbit satellites, but no significant change is identified possibly due to inappropriate satellite position. The above TEC measurements, known collectively as global navigation satellite system（GNSS） TEC techniques, exhibit an unprecedented capability of remote sensing and will hopefully provide new insight into the dynamics of magnetosphere.

关 键 词：总电子含量(TEC) 磁层压缩 行星际激波 

分 类 号：P228.4[天文地球—大地测量学与测量工程] P353[天文地球—测绘科学与技术]