基于地基GPS研究台风引起电离层TEC的变化特征

利用GPS研究电离层,具有其他探测技术所没有的全天候、高分辨率、大范围等优点.本文采用双频GPS数据提取区域电离层电子浓度总含量（TEC）,并结合全球电离层地理（GIM）数据,借助滑动四分位距法建立TEC背景值.研究了台风“莫兰蒂”对其经过区域及登陆地点电离层TEC的影响.分析表明,台风登陆厦门前一天,厦门地区电离层TEC发生了较强的正扰动,登陆后第二天,TEC发生了小尺度的负扰动;台风临近台湾岛前,东南沿海和台湾岛区域电离层出现了大范围的正异常扰动,其值为15～20 TECU,持续时间10 h.结合厦门和台湾岛的地形,推测此次TEC异常原因是由于台风所激发的声重力波传播到电离层高度,造成了电离层的异常扰动. 

Study on the Characteristics of the Ionospheric TEC Disturbances Caused by Typhoon Based on Ground Based GPS Data

The way to study ionosphere used the Global Position System has many advantages of all-weather, high-resolution and wide-range. Based on the sliding interquartile range method and with the ionospheric TEC data which is extracted from GPS dual observation and GIM, this paper studies the feature of the ionospheric TEC disturbances caused by typhoon at its passage areas and landing site. The results show that the day before the typhoon landed in Xiamen, the TEC has a strong positive disturbance, and there is a small-scale negative disturbance occurred the day after landing; Before the typhoon approached Taiwan Island, there is a widely range of positive ionospheric anomaly disturbances whose value is 15～20 TECU and the duration is 10 h in the typhoon-affected areas. Combined with the terrain of Xiamen and Taiwan Island, it is inferred that the TEC anomaly is due to the propagation of acoustic gravity waves induced by typhoon into the ionosphere altitude.