Modeling of the ionospheric earthquake precursors generated by various electric field sources

Abstract

The numerous experimental GPS (Global Positioning System) data show that there exists a correlation between anomalous disturbances in the TEC (total electron content) of the ionosphere and earthquakes of magnitude M5 or larger. The very probable reason of the NmF2 and TEC disturbances observed before earthquakes is the vertical drift of the F2-region ionospheric plasma under the influence of the zonal electric field of seismogenic origin. We have investigated the ionospheric earthquake precursors’ characteristics for the electric potential sources of different kinds (dipole and monopole – positive) by means of numerical modeling with the UAM (Upper Atmosphere Model). A comparison of the model results with GPS TEC observations for the earthquake in Greece (8 January 2006) shows that the best agreement between simulated data and observations for mentioned earthquake takes place in cases of the dipole electric field sources.