FORMOSAT-7/COSMIC-2 IVM observes ionospheric plasma ripples triggered by the 15 January 2022 Tonga volcano eruption

Ionospheric signatures of the 15 January 2022 Tonga volcano eruption are observed by FORMOSAT-7/COSMIC-2 (F7/C2) ion density (Ni). Standard deviation (STD) and coefficient of variance (Cv) of Ni as well as Receiver Operating Characteristics (ROC) curves are employed to statistically examine the ionospheric perturbations. Results show that when F7/C2 satellites pass through the wavefront of atmospheric disturbances, Ni as well as its associated STD and Cv are significantly greater than their monthly medians. Statistical analysis shows that the eruption wave with a front speed of 150-300 m/s most likely contributes to the ionospheric disturbance signatures.