利用GPS双频观测量可获取电离层总电子含量(Total Electron Content,TEC),以监测区域上空电离层的分布和变化特征,从而可以发现不同尺度的电离层异常。该文采用2004年上海地区GPS综合应用网(SCGAN)以及中国地壳运动监测网络(CMONC)的部...利用GPS双频观测量可获取电离层总电子含量(Total Electron Content,TEC),以监测区域上空电离层的分布和变化特征,从而可以发现不同尺度的电离层异常。该文采用2004年上海地区GPS综合应用网(SCGAN)以及中国地壳运动监测网络(CMONC)的部分台站的观测,计算得到1年时间序列的TEC数据,来研究长三角地区上空的电离层TEC的变化与活动。应用这些数据,综合利用高斯权函数和滑动平均等几种数据处理方法,重点分析和讨论了长三角地区上空电离层的周日变化、周年变化和季节性变化特性,揭示了电离层冬季异常等现象。同时,通过对1年时间序列TEC进行谱分析,得到了其相应的变化周期。展开更多
We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of Ma...We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of March 11, 2011. The data include outgoing long wave radiation （OLR）, GPS/TEC, lower Earth orbit ionospheric tomography and critical frequency foF2. Our first results show that on March 7th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting from this day in the lower ionosphere also there was confirmed an abnormal TEC variation over the epicenter. From March 3 to 11 a large increase in electron concentration was recorded at all four Japanese ground-based ionosondes, which returned to normal after the main earthquake. The joint preliminary analysis of atmospheric and ionospheric parameters during the M9 Tohoku, Japan earthquake has revealed the presence of related variations of these parameters implying their connection with the earthquake process. This study may lead to a better understanding of the response of the atmosphere/ionosphere to the great Tohoku earthquake.展开更多
文摘利用GPS双频观测量可获取电离层总电子含量(Total Electron Content,TEC),以监测区域上空电离层的分布和变化特征,从而可以发现不同尺度的电离层异常。该文采用2004年上海地区GPS综合应用网(SCGAN)以及中国地壳运动监测网络(CMONC)的部分台站的观测,计算得到1年时间序列的TEC数据,来研究长三角地区上空的电离层TEC的变化与活动。应用这些数据,综合利用高斯权函数和滑动平均等几种数据处理方法,重点分析和讨论了长三角地区上空电离层的周日变化、周年变化和季节性变化特性,揭示了电离层冬季异常等现象。同时,通过对1年时间序列TEC进行谱分析,得到了其相应的变化周期。
基金NASA Goddard Space Flight Center,Chapman University and European Framework program #7 project PREEARTHQUAKE for their kind support
文摘We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of March 11, 2011. The data include outgoing long wave radiation （OLR）, GPS/TEC, lower Earth orbit ionospheric tomography and critical frequency foF2. Our first results show that on March 7th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting from this day in the lower ionosphere also there was confirmed an abnormal TEC variation over the epicenter. From March 3 to 11 a large increase in electron concentration was recorded at all four Japanese ground-based ionosondes, which returned to normal after the main earthquake. The joint preliminary analysis of atmospheric and ionospheric parameters during the M9 Tohoku, Japan earthquake has revealed the presence of related variations of these parameters implying their connection with the earthquake process. This study may lead to a better understanding of the response of the atmosphere/ionosphere to the great Tohoku earthquake.
