2017年9月强磁暴及引发的电离层扰动  

Strong geomagnetic storm and induced ionospheric disturbance in September 2017

作　　者：尹汇民 孔建[1] 安家春[1] 王泽民[1] YIN HuiMin;KONG Jian;AN JiaChun;WANG ZeMin(Chinese Antarctic Center of Surveying and Mapping,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学中国南极测绘研究中心,武汉430079

出　　处：《地球物理学进展》2021年第1期96-104,共9页Progress in Geophysics

基　　金：国家自然科学基金(41604002,41776195)资助。

摘　　要：本文研究内容基于2017年9月7日20UT开始的一次强烈的地磁暴事件.这是一次"特殊"的磁暴,在持续两天的磁暴期间,出现了两次强度较大的主相,相隔约14 h.本文通过多项磁暴指数进行研究,发现各项指数均出现两个峰值,两次主相对应的磁暴环电流指数(Dst)最小值都低于100 nT.强磁暴引发了剧烈的电离层扰动,本文中采用南北极区的4个全球导航卫星系统(GNSS)跟踪站的数据展开研究,并将垂直路径总电子含量(VTEC)作为指标进行分析,发现电离层扰动幅度在南北极区存在较大差异.南极地区的站点的电离层扰动幅度要远高于北极地区,其中MCM4站VTEC水平甚至超出平时300%.此外,极区的VTEC变化趋势与地磁指数的变化呈现出基本一致的状态,表现为在磁暴的两次主相时均可以观测到强烈的电离层正暴.本文还选取位于中国东半部的3个电离层测高仪站数据,以电离层层临界频率(f0F2)为依据,采用相似衰落法对中低纬度大尺度电离层行扰(LSTID)进行了研究,发现其传播速度衰减明显且不同高度层面水平传播速度有差异,在300 km高度,LSTID从漠河站传播至武汉站的平均水平传播视速度为340 m/s,从武汉站传播至三亚站,这一速度为200 m/s;在400 km高度,这两个速度分别为375 m/s、215 m/s;LSTID传播的方向为南偏西约20°.The research content of this article is based on a strong geomagnetic storm event starting at 20 UT on September 7, 2017. This is a "special" magnetic storm. During the magnetic storm that lasted for nearly two days, two major phases of comparable intensity appeared, separated by 14 h. In this paper, a number of magnetic storm indices were researched and it was found that each index showed two peaks, and the minimum value of the Dst index corresponding to the two main times was less than 100 nT. Strong magnetic storms caused severe ionospheric disturbances. In this paper, data from four Global Navigation Satellite System(GNSS) tracking stations in the Antarctic and Arctic regions were used for research. The total electron content in the vertical path(VTEC) was used as an indicator to analyze the ionospheric layer. The amplitude of the disturbance varies widely between the north and south poles. The amplitude of ionospheric disturbances at stations in the Antarctic region is much higher than that in the Arctic region, and the VTEC level at MCM4 station is even 300% higher than usual. In addition, the change trend of the VTEC in the polar region and the change of the geomagnetic index show a basically consistent state, which shows that a strong positive ionospheric storm can be observed in the two main phases of the magnetic storm. This paper also selects three ionospheric altimeter stations located in the eastern half of China. Based on the critical frequency of the ionospheric layer F2(f0F2), a similar fading method is used to calculate some parameters of the large-scale traveling ionospheric disturbance in the middle and low latitudes(LSTID) and it was found that the propagation velocity was significantly attenuated and the horizontal propagation velocity at different altitudes was different. At an altitude of 300 km, the average horizontal propagation velocity of LSTID from Mohe Station to Wuhan Station was 340 m/s, from Wuhan Station to Sanya Station This speed is 200 m/s;at a height of 400 km, the two speeds

关 键 词：磁暴 VTEC 电离层正暴 F0F2 相似衰落法 LSTID 

分 类 号：P352[天文地球—空间物理学]