The 2022 Hunga Tonga Eruption Triggered Atmospheric Waves Propagating Globally from the Surface to the Edge of Space

The January 2022 Hunga Tonga–Hunga Haʻapai eruption was one of the most explosive volcanic events of the modern era, producing a vertical plume which peaked > 50km above the Earth. The initial explosion and subsequent plume triggered atmospheric waves which propagated around the world multiple times. A global-scale wave response of this magnitude from a single source has not previously been observed. We used a comprehensive set of satellite and ground based observations to quantify this response from surface to ionosphere. A broad spectrum of waves was triggered by the initial explosion, including Lamb waves at all heights and gravity waves in the middle atmosphere. Gravity waves have not previously been observed propagating at this speed or over the whole Earth from a single source. Latent heat release from the plume remained the most significant individual gravity wave source worldwide for >12 hours, producing circular wavefronts visible across the Pacific basin in satellite observations. A single source dominating such a large region is also unique in the observational record. The Hunga Tonga eruption represents an important natural experiment in how the atmosphere responds to a sudden point-source-driven state change, which is of use for improving weather and climate models.