Evolution of the Atmospheric Pressure Signal from the Tonga Volcano with Distance from It

A model of propagation of an atmospheric pressure signal from the eruption of the Hunga Tonga−Hunga Haʻapai volcano is proposed. This model is used to explain some patterns in the change in the form of the observed signal with an increase in the distance from the volcano. It is based on the solution of the linearized Korteweg–de Vries (KdV) equation, which describes the change in the Lamb wave form as a function of the distance from a source. We compare the observed and model signals obtained as a superposition of the Lamb wave and acoustic modes calculated for three infrasound stations (IS22, IS24, and IS30). The energy of the volcanic eruption is estimated using the fluctuation amplitude of the atmospheric pressure and the characteristic duration of the signal recorded at the infrasound stations closest to the volcano.