天地基综合观测的东日本大地震电离层异常分析

介绍了地震电离层前兆的主要特性，并给出了掩星电离层电子密度峰值位置的标高估计技术。利用天地基电离层观测数据，综合分析了2011年3月11日日本9.0级大地震发生前的电离层异常变化，发现地震前3天内电离层f0F2异常扰动、相对垂直总电子含量（VTEC）扰动以及电子密度峰值处标高（Hs）增加等多种异常现象。分析了地磁活动和太阳活动等因素后，认为其可能与地震有一定关联，表明电离层异常变化对于地震短期预报具有重要参考意义。

Ionospheric anomalies analysis of Eastern Japan Great Earthquake based on comprehensive observed data from the space and the ground

The main phenomenological features of ionospheric precursors of earthquakes are introduced firstly,and the ionospheric scale height estimation method at the height of maximum electron density is studied by the constellation observing system for meteorlogy,ionosphere and climate(COSMIC)occultation data products.Then,the anomalous changes of ionospheric parameters before Eastern Japan Great Earthquake happened on Mar 11,2011 are analyzed based on comprehensive observed data from the ground based ionosonde,GPS and spaceborne GPS occultation.It is shown that several ionospheric anomalies appeared three days before the earthquake,including that ionospheric f0F2 and relative vertical total electron content(VTEC)existed anomalous disturbance,and ionospheric Hs increased.After we analyze the impact of geomagnetic activity and solar activity,we think that all the results are related to Eastern Japan Great Earthquake.It is demonstrated that ionospheric anomalous changes can offer important information for the short-term earthquake prediction.