Spectral characteristics of ionospheric disturbances over the
Southwestern Pacific from the January 15, 2022 Tonga eruption and
On January 15, 2022, Tonga’s Hunga Tonga-Hunga Ha’apai (HTHH) volcano
violently erupted, generating a tsunami that killed three people.
Acoustic-gravity waves propagated by the eruption and tsunami caused
global complex ionospheric disturbances. In this paper, we study the
nature of these perturbations from Global Navigation Satellite System
observables over the southwestern Pacific. After processing data from
818 ground stations, we detect supersonic acoustic waves, Lamb waves,
and tsunamis, with filtered magnitudes between 1 and 7 Total Electron
Content units. Phase arrivals appear superpositioned up to
~1000 km from HTHH and are distinct by
~2200 km. Within ~2200 km, signals have
an initial low-frequency pulse that transitions to higher frequencies.
We note the presence of a faster perturbation generated one hour
post-eruption which crosses the tsunami disturbance
~3000 km from HTHH, potentially contributing to
premature land arrivals. Lastly, the arrival of tsunami-generated
disturbances coincides with deep-ocean observations.