Disturbances of Doppler Frequency Shift of Ionospheric Signal and of Telluric Current Caused by Atmospheric Waves from Explosive Eruption of Hunga Tonga Volcano on January 15, 2022

Abstract

After the explosive eruption of the Hunga Tonga volcano on 15 January 2022, disturbances were observed at a distance of about 12,000 km in Northern Tien Shan and regarded variations in the atmospheric pressure, in telluric current, and in the Doppler frequency shift of ionospheric signal. At 16:00:55 UTC, a pulse of atmospheric pressure was detected there, with peak amplitude of 1.3 hPa and propagation speed of 0.3056 km/s, equal to the velocity of Lamb waves. In the variations in the Doppler frequency shift, disturbances of two types were registered on the 3212 km and 2969 km long inclined radio paths, one of which arose as a response to the passage of a Lamb wave (0.3059 km/s) through the reflection point of the radio wave and another as reaction to an acoustic-gravity wave (0.2602 km/s). Two successive perturbations were also detected in the records of telluric current at the arrival times of the Lamb and acoustic-gravity waves at the registration point. According to the parameters of the Lamb wave, the energy transfer into the atmosphere upon the explosion of the Hunga Tonga volcano was roughly estimated to be 2000 Mt of TNT equivalent.