Global Electromagnetic Disturbances Caused by the Eruption of the Tonga Volcano on 15 January 2022

The study is devoted to the analysis of geomagnetic field disturbances and the response of the Schumann resonance (SR) during the eruption of the Tonga volcano in 2022. The data on geomagnetic field variations at distances from 800 to 15,000 km from the volcano according to the INTERMAGNET network and parameters of SR signals recorded at Mikhnevo Observatory in Russia were used. The source of global geomagnetic disturbances are acoustic-gravity waves (AGWs), which caused changes in ionospheric conductivity, values of ionospheric currents, and the geomagnetic field. The propagation velocity of magnetic disturbances 263 +/- 5 m/s, corresponding to the AGWs velocity, was determined and an independent estimate of the time of the eruption phase that caused the generation of the atmospheric wave (4:14 +/- 10 UT) was obtained. A new method of processing the results of measurements of SR disturbance with a time resolution of 5 min instead of the usual 10-15 min allowed not only to detect but also to study this phenomenon in detail. The peculiarities of signals related to the number and energy of lightning discharges were revealed. Synchronous measurements of SR signals and geomagnetic field variations in a single observatory for the first time allowed to obtain an independent estimate of the eruption time and the electromagnetic disturbance propagation rate. Plain Language Summary The eruption of the Tonga volcano on 15 January 2022 caused global disturbances in the geomagnetic field and Schumann resonances. The paper shows that the source of disturbance of Schumann resonances during the eruption was increased thunderstorm activity in the volcanic cloud. Disturbances in the geomagnetic field are caused by acoustic-gravity waves resulting from the eruption. A comprehensive analysis of the data made it possible to determine the time of the beginning of the eruption.