[P-EM27] Physics and Chemistry in the Atmosphere and Ionosphere

[PEM27-P07] Simulation Results for the Ionospheric Density Disturbances Triggered by Earthquake Rayleigh Waves

*Chia-hung CHEN¹, Mitsuru MATSUMURA², Charles Lin¹, Akinori SAITO³, Jann-yenq LIU⁴ (1.Department of Earth Sciences, National Cheng Kung University, Taiwan, 2.National Institute of Polar Research, 3.Department of Geophysics, Graduate School of Science, Kyoto University, 4.Institute of Space Science, National Central University, Taiwan)

Keywords:Earthquake, Rayleigh wave, Ionosphere, Plasma density disturbance

During the great earthquake event of M9.0 Tohoku earthquake on 11 March 2011 in Japan, previous studies detected the horizontal wave structure of ionospheric total electron content (TEC) disturbances by a dense ground-based GPS receiver network. These results suggested that the ionospheric TEC disturbances could be caused by the earthquake-triggered seismic surface, acoustic-gravity, and tsunami waves, which are distinguished by the different propagation velocities, durations, and periods. In order to further investigate the vertical coupling effect for the ionospheric plasma density disturbances, this study employed a three-dimensional, non-linear, compressible numerical model. This model simulated the disturbances of neutral mass densities from the surface to lower, upper atmosphere and the ionosphere, by specifying the surface displacement triggered by the earthquake, such as the rayleigh waves, at the model lower boundary. The results show that the TEC disturbances have two types of the propagation waves, first horizontal waves and slow co-centric waves. These might be caused by the neutral wind dynamo effect and the ion-neutral collision along the magnetic field.