Ionospheric anomaly before the 2011 Tohoku Mw 9.0 earthquake

:Using Computerized Ionospheric Tomography (CIT) in combination with GPS observations from the Crustal Movement Observation Network of China (CMONOC), this study reconstructed the electron density distributions over China before the 2011 Tohoku Mw 9.0 earthquake and discovered a prominent ionospheric anomaly on March 8, 2011. Analysis of the solar-terrestrial space environment around the time of the Tohoku earthquake indicated that the March 8 ionospheric anomaly was likely related to the earthquake. Finally, the paper discusses the drift of the ionospheric anomaly, which was infeered from the anomaly being observed by GPS reference sites in China.