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利用中国大陆构造环境监测网络及全球GPS服务系统提供的中国及其周边地区的246个GPS接收台站的TEC观测资料,观测研究了2011年5月28日一次中等强度磁暴期间中国地区出现的大尺度电离层行进式扰动(LSTID),并给出了中国地区的二维TEC扰动图像.结果表明:在磁暴恢复相期间,我们一共监测到两个LSTID事件,一个发生在午夜前的中国西南地区,另一个发生在午夜后的东北地区.TEC二维成像结果清晰地显示了两次LSTID在中国地区的连续传播过程,西南地区午夜前的LSTID由低纬向中纬沿北偏东的方向传播,其持续时间约为60min,水平传播距离约1200km,等相面的宽度最大约500km;东北地区午夜后的LSTID由中纬向低纬沿南偏西的方向传播,其持续时间约为70min,水平传播距离约1200km,等相面的宽度最大可达1400km.对TEC扰动进行互谱分析得到两次LSTID的传播参量,发现午夜前的LSTID的水平传播相速度和相对扰动振幅的平均衰减率都比午夜后的LSTID的要大,这可能是由午夜前西南地区较高的背景垂直TEC0及背景大气温度引起的.研究还表明,午夜后的LSTID是由北极区活动激发的大气声重波产生的,通过对高纬地区水平地磁分量H的分析,可以估计出其激发源应位于140°E以东,42°N以北的1400～2600km范围之内;而对于午夜前的LSTID,则可能是由赤道电集流引起的焦耳加热激发的大气声重波产生的.
Using the TEC observation data of 246 GPS receiving stations in China and its surrounding area provided by the China Mainland’s tectonic environment monitoring network and the global GPS service system, observing and observing the large-scale occurrence of large-scale geomagnetic storms in China during the medium-intensity storms on May 28, 2011 Scale LSSTD and the two-dimensional TEC perturbation images in China are presented.The results show that during the period of the storm surge, we observed a total of two LSTID events, one in southwestern China , And the other occurred in the northeast after midnight.The two-dimensional TEC imaging results clearly show the continuous propagation of two LSTIDs in China, and the LSTID in the southwest region spread from north latitude to mid-latitude in the north-easterly direction , The duration of which is about 60min, the horizontal propagation distance is about 1200km, and the width of the isopathic plane is about 500km. The LSTID of the northeastern region spreads from south to latitude to south westward at a low latitude of about 70min, The horizontal propagation distance is about 1200km, and the width of isobaric surface is up to 1400km. Cross-spectrum analysis of TEC disturbances results in two LSTID propagation parameters and the horizontal transmission of LSTID before midnight The average decay rate of velocity and relative disturbance amplitude is larger than that of LSTID after midnight, which may be caused by the higher background vertical TEC0 and background atmospheric temperature in the southwest of midnight.Studies also show that LSTID after midnight is caused by By analyzing the horizontal magnetic field H in the high latitudes, it can be estimated that the excitation source should be located within the range of 1400 ~ 2600km east of 140 ° E and north of 42 ° N For LSTID before midnight, it may be caused by Joule heating-induced atmospheric sound waves caused by the equatorial current.