Evidence of Lightning and Gravity wave signatures produced by the Hunga-Tonga Volcanic eruption on Global geomagnetic data

Abstract

Abstract Global disruptions were noticed after the Hunga-Tonga volcanic eruption on January 15th 2022, which released an enormous amount of mass and energy into the atmosphere. Since there are many facets associated with this event, the primary focus of this investigation is on the following: (i) changes in the Schumann resonance (SR) modes as a result of the discharge of lightning strikes and (ii) global geomagnetic disturbances due to acoustic-gravity waves (AGWs). The results of our analysis show the noticeable changes in SR frequency modes (i.e. 7 to 21 Hz), between 04:15 and 05:45 UT hours in the high-frequency 64Hz scalar magnetic field (F) data derived from Induction coil magnetometer at Patiyasar (Himalayan region) and the propagation velocity of geomagnetic disturbances is found to be 269.68 ± 5 m/s, corresponding to the acoustic-gravity wave velocity, derived from the scalar magnetic field from the fluxgate magnetometers from 20 geomagnetic observatories (18 INTERMAGNET and 02 non- INTERMAGNET) world-wide located between 800 and 16000 km away from Tonga volcano. By comparing the lag time between the observed Schumann resonance and the negative bay, this study confirmed the velocity of the acoustic-gravity wave (296.76 ± 5 m/s, which closely corresponds to the estimated AGWs velocity: 269.68 ±5 m/s) with a delay of 11.48 ± 0.25 UT hour from a single geomagnetic observatory, Patiyasar (15000 km from Tonga). The variance in velocities could be attributed to the role of atmospheric-ionospheric winds and different ionosphere conditions.