open access

https://hdl.handle.net/2115/94196

Atmospheric resonant oscillations by the 2022 January 15 eruption of the Hunga Tonga–Hunga Ha'apai volcano from GNSS-TEC observations

英語

Remote sensing of volcanoes

2024-03

Royal Astronomical Society

Geophysical Journal International

236(3)

1840-1847

Continuous Plinian eruptions often excite atmospheric modes of ∼3.7 and ∼4.4 mHz, which are observed as harmonic oscillations of ionospheric total electron content (TEC) by global navigation satellite system (GNSS) receivers. Such TEC oscillations started shortly after the great eruption of the Hunga Tonga–Hunga Ha’apai (HTHH) submarine volcano at ∼4:14 UT, on 2022 January 15. Here I analyse GNSS data at stations within ∼4000 km from the volcano to study temporal and spatial distribution of such atmospheric modes. Strong ∼3.7 mHz TEC oscillations in near fields started shortly after the eruption onset and propagated outward with the sound speed from HTHH. Later such TEC oscillations became strong again with the amplitude peak at the distance ∼1400 km from HTHH. Such far field oscillations occurred also above New Zealand and the Solomon Islands, ∼3000 km from HTHH. Their amplitudes seem correlated with those of the 0 S29 solid earth mode, suggesting that vertical surface vibrations underneath may play a role in maintaining the atmospheric mode. Onset of the far field TEC oscillations are synchronized with the local sunrise, possibly controlled by diurnal changes in the ionospheric electron density.

学術雑誌論文

Version of Record

This article has been accepted for publication in "Geophysical Journal International" © The Authors 2024. Published by Oxford University Press on behalf of The Royal Astronomical Society.

0956-540X

1365-246X