Seismo-Traveling Ionospheric Disturbances Triggered by the M9.0 2011 Tohoku Earthquake Probed by FORMOSAT- 3/COSMIC and Ground-Based GPS receivers

Abstract:

This paper reports seismo-traveling ionospheric disturbances in the electron density and total electron content (TEC) profiles of FORMOSAT- 3/COSMIC (F3/C) during the 11 March 2011 M9.0 Tohoku earthquake. The Abel inversion and the vertical gradient (differential) process act as the low- and high-pass filters, respectively. It is found that fluctuations with the wavelength of 70-50km and less become pronounced during the earthquake period.  Results demonstrate that the radio occultation is suitable to probe vertical fluctuation structures in the ionosphere.  On the other hand, the Fourier Transform analysis displays that the TEC fluctuations derived from GPS receiving stations in Japan yields prominent fluctuations of 2-3 and 5-6 mHz around epicenter right after the earthquake occurrence.