A case study of the three-dimensional co-seismic ionospheric disturbance evolution

The total electron content is an integrated value of ionospheric electron density (Ne) along the satellite-receiver ray path; therefore, it cannot directly resolve ionospheric disturbances in the vertical direction. In this work, to better understand the continuous evolution of co-seismic ionospheric disturbances (CIDs) at different altitudes, we conducted an accurate three-dimensional (3-D) visualization of CIDs associated with the 2011 M9.0 Tohoku-Oki earthquake based on the computerized ionospheric tomography technique. The results clearly revealed the 3-D morphological discrepancies of CIDs caused by Rayleigh waves, acoustic-gravity waves originating from the epicenter, and internal gravity waves induced by the tsunami waves. Further, we investigated the propagation and distribution of Ne disturbances along altitude. It was found that Ne disturbances triggered by different wave patterns exhibited different evolution characteristics in the vertical direction. The application of 3-D ionospheric detection has the potential to enhance the robustness of the earthquake and tsunami early warning systems.