Balloon-borne observations of infrasound waves from the January 2022 eruption of the Hunga volcano, Tonga (Invited)
Résumé
The 15 January 2022 eruption of the Hunga volcano (Tonga) generated a rich spectrum of waves, some of which achieved global propagation. Among numerous platforms monitoring the event, two long-duration balloons flying at 20 km altitude over the tropical Pacific recorded unique observations of infrasonic wave arrivals within the stratosphere. Combined with ground-based measurements from the infrasound network of the International Monitoring System, these observations provide precious insight into the eruption process in terms of event chronology and altitude distribution of energy release. They highlight previously unobserved long-range propagation of infrasound modes, detecting five revolutions of the infrasound waves. A comparison between ground- and balloon-based measurements emphasizes generally larger signal-to-noise ratios onboard the balloons and further demonstrates their potential for infrasound studies.