基于ARMA模型磁暴抑制的地震TEC异常分析

Analysis of Anomalies in Seismic TEC Data Based on ARMA Magnetic Storm Suppression Model

地震孕育的过程中会影响电离层的粒子浓度(TEC),因此可以通过TEC数据分析地震异常信息,但是TEC数据相较地震事件受太阳活动影响更大,所以以往的研究通常只能选择太阳活动较为平静的时期。受磁暴影响TEC数据无法正常反应2021年云南大理州等地的地震异常信息,因此抑制磁暴干扰就显得格外重要。在滑动四分位法的基础上提出一种基于ARMA模型的TEC数据磁暴抑制方法,通过重新拟合磁暴发生前后的TEC数据,从而代替原始数据进行分析,在一定程度上降低磁暴对地震的信息的影响,然后提出一种地震特征及其相关性的模型对TEC异常和地震事件的相关性程度进行分析。基于IGS数据分析中心提供的全球电离层电子浓度数据,分别对2021年云南大理州漾濞县6.4级地震和青海果洛州玛多县7.4级地震进行仿真分析,分别使用传统的滑动四分位法和滑动窗口法,并通过提出的相关性模型对磁暴抑制前后的特征和事件相关性结果进行对比,结果表明去除磁暴后的特征与地震相关性增加约13-18%。

Total electron content(TEC)changes as an earthquake develops,so the seismic anomaly information can be analyzed through TEC data.However,TEC data is more sensitive to solar activity than seismic events,so previous studies can only choose the time period with relatively quiet solar ac-tivity.Affected by the magnetic storm,TEC data cannot normally reflect the seismic anomaly infor-mation in Dali Prefecture,Yunnan Province in 2021.Therefore,it is particularly important to sup-press the magnetic storm interference.Based on the sliding quartile method,a magnetic storm suppres-sion method for TEC data is proposed using the ARMA model.By refitting the TEC data before and after the magnetic storm instead of using the original data,the influence of magnetic storm on seismic information can be reduced to a certain extent.Then,a model of seismic features and their correlation is proposed to analyze the correlation between TEC anomalies and seismic events.Based on the global ionospheric TEC data provided by the IGS data analysis center,the 2021 Ms6.4 earthquake in Yanghe County,Dali Prefecture,Yunnan Province and the Ms7.4 earthquake in Maduo County,Guoluo Pre-fecture,Qinghai Province are simulated and analyzed respectively.The traditional sliding quartile method and sliding window method are used respectively,and the features and event correlation re-sults before and after magnetic storm suppression are compared through the proposed correlation mod-el.The results show that the correlation between earthquakes and features after removing magnetic storms increases by about 13-18%.