Tonga eruption triggered waves propagating globally from surface to edge
of space
Marie Bouillon
LATMOS/IPSL, Sorbonne Université, UVSQ, CNRS, Paris, France, LATMOS/IPSL, Sorbonne Université, UVSQ, CNRS, Paris, France
Author ProfileAbstract
The January 2022 Hunga Tonga–Hunga Haʻapai eruption was one of the most
explosive volcanic events observed in the modern era, producing a
vertical plume which peaked more than 50km above the Earth. The initial
explosion and subsequent plume triggered atmospheric waves which
propagated around the world multiple times. Here, we combine a
comprehensive set of satellite and ground-based observations to analyse
and quantify this wave response, from surface to ionosphere. A broad
spectrum of waves was triggered by the initial explosion, including Lamb
waves propagating at 318.2±6 ms-1 at surface level and between 308±5 to
319±4 ms-1 in the stratosphere, and fast gravity waves propagating at
238±3 to 269±3 ms-1 in the stratosphere. Atmospheric gravity waves at
sub-ionospheric heights have not previously been observed propagating
either at this speed or over the whole Earth from a single identifiable
source. Latent heat release from water and hot ash in the plume remained
the most significant individual gravity wave source at any location for
the next 12 hours, producing circular wavefronts visible across the
Pacific basin in satellite gravity wave observations. A single source
dominating such a large region is also unique in the observational
record. The Hunga Tonga eruption represents a key natural experiment in
how the atmosphere responds to a sudden point-source-driven state
change, which will be of significant use for improving atmospheric
weather and climate models.