Physics-Based Modeling of Earthquake-Induced Ionospheric Disturbances

To numerically simulate earthquake-induced ionospheric disturbances, we extend the Wave Perturbation-Global Ionosphere-Thermosphere Model, which was originally developed for tsunami-ionosphere coupling via gravity waves, to the case of earthquake-ionosphere coupling via acoustic-gravity waves. The new Wave Perturbation-Global Ionosphere-Thermosphere Model represents epicentral crustal movements by a point source specified with the ground motion data from seismic measurements. The model then solves for the neutral atmospheric perturbations generated by spherical acoustic-gravity waves and the resulting ionospheric plasma perturbations over the epicentral area. We apply the model to simulate the near-field ionospheric disturbances during two major earthquake events: the 2011 Tohoku-Oki, Japan, and the 2015 Illapel, Chile, events. To validate the results, we extract receiver-to-satellite total electron content perturbations from the simulations and compare them to the corresponding slant total electron content perturbations from Global Positioning System observations. We find good agreement on magnitudes and arrival times between the simulations and observations.