Uplift of the ionosphere by tropospheric and thermospheric Lamb waves induced by the 2022 Tonga volcanic eruption

Abstract On 15 January 2022, the Tonga submarine volcano eruption generated atmospheric shocks, air pressure perturbations, tsunamis, etc., inducing traveling atmospheric disturbances (TADs) and traveling ionospheric disturbances (TIDs). Data from the Himawari-8 satellite, ionosondes, as well as nearby barometers and tide gauges are employed to study the perturbations over Taiwan and Japan. Ionograms reveal that TIDs associated with the thermospheric and tropospheric Lamb wavefronts propagate with the northwestward (upward) speeds of 539.0 ± 22.3 and 338.3 ± 4.0 m/s (21.0 ± 5.0 and 12.4 ± 3.3 m/s), which further uplift the ionosphere by 86–155 and 50–110 km, respectively. The latter TID is followed by distinct TAD signatures, including prominent near-Earth surface air pressure pulses and significant sea level fluctuations, whereas the former one is not. The two TIDs significantly uplift the ionosphere which increase the growth rate of Rayleigh–Taylor instability, and result in the occurrence of ionospheric spread-F layers.