GNSS-based atmosphere sounding on the earthquake and tsunami induced atmosphere-ionosphere perturbations

Traveling ionospheric disturbances (TIDs) induced by acoustic-gravity waves (AGWs) in the neutral atmosphere are observable in trans-ionospheric radio signals such as Global Navigation Satellite System (GNSS) signals. In this research, we designed a wavelet-based method to enhance the detection and estimation for sounding the presence of atmosphere-wave-induced TIDs using measurements collected from GNSS networks near the epicenter of the March 11, 2011 Tohoku-Oki earthquake and the resulting tsunami. A comparison of GNSS/GPS based observations, global ionosphere-thermosphere model (GITM simulations, JPL´s tsunami model simulations and ground motions are analyzed to understand the atmosphere-ionosphere responses in this tsunami/earthquake event. Through use of the wavelet coherence analysis, we are able to identify major wave trains presented in the data collected from networks (such as Japan GEONET and U.S. PBO), with different dominant frequency bands and characteristics. They are mostly due to the infrasound signals and gravity waves originated from the epicenter, Rayleigh waves from the ground surface motions, and tsunami propagation.