日本九州岛地震震前电离层TEC异常

Ionospheric Anomaly before Kyushu,Japan Earthquake

采用IGS发布的GIM数据,提出了一种结合滑动时窗法和临近格网点电离层TEC相关性分析法的联合分析方法,研究了震前电离层异常变化与地震的关系。通过分析震区附近5个格网点TEC的异常变化情况,发现震前电离层TEC发生明显异常变化,且格网点之间的TEC序列相关性受地震显著影响;通过分析二维电离层图的TEC异常空间分布,发现震前三天震中附近分别出现6h、12h和6h的异常。最后利用电离层层析的方法,对电离层异常时刻进行了电子密度的反演,进一步分析了电子密度在电离层异常时刻的分布情况。

GIM data released by IGS is used in the article and a new method of combining the Sliding Time Window Method and the Ionospheric TEC correlation analysis method of adjacent grid points is proposed to study the relationship between pre-earthquake ionospheric anomalies and earthquake.By analyzing the abnormal change of TEC in the 5grid points around the seismic region,the abnormal change of ionospheric TEC is found before the earthquake and the correlation between the TEC sequences of lattice points is significantly affected by earthquake.Based on the analysis of the spatial distribution of TEC anomaly,anomalies of 6h,12 hand 6hwere found near the epicenter three days before the earthquake.Finally,ionospheric tomographic technology is used to do tomographic inversion on electron density.And the distribution of the electron density in the ionospheric anomaly is further analyzed.