Stratosphere Perturbed by the 2011 Mw9.0 Tohoku Earthquake

This study examined the FORMOSAT-3/COSMIC radio occultation soundings of total electron content in the ionosphere (from 150 to 550 km) and refractivity index in the lower atmosphere (from 0 to 60 km) after/during the 2011 Mw9.0 Tohoku earthquake/tsunami. The refractivity index observations show the first evidence of the Tohoku earthquake/tsunami-induced vertical oscillations in the lower atmosphere. The atmospheric oscillations with vertical wavelength ranging from 0.5 to 8 km and from 10 to 40 km, respectively, appear in the stratosphere and ionosphere after the earthquake onset. The short vertical wavelengths suggest that the oscillations are the atmospheric oscillatory tail due to the wavefront of the earthquake/tsunami. The radio occultation technique is a tool for detecting the atmospheric waves induced by earthquake or some other sources.