Simulation study of atmosphere-ionosphere variations driven by the eruption of Hunga Tonga-Hunga Ha'apai on 15 January 2022

Abstract

The volcano of Hunga Tonga-Hunga Ha’apai in Tonga erupted on 15 January 2022, generating severe disturbances in the atmosphere and the ionosphere. This event provided us with large amount of data of the atmosphere and the ionosphere, and various kinds of observational studies have been made. Recently several simulation studies have also been made to reproduce and understand the atmosphere-ionosphere variations driven by the volcanic eruption. Although the simulation studies have reproduced the global variations of the atmosphere and the ionosphere successfully, phenomena related with acoustic waves have not been fully investigated. We employed an axisymmetric three-dimensional nonhydrostatic atmospheric model and the whole atmosphere-ionosphere coupled model GAIA. We found that the simulation can produce various kinds of atmospheric waves generated by the eruption, such as acoustic waves, gravity waves, Lamb waves, Pekeris waves, and TIDs concentrically propagating from the eruption site, and atmospheric oscillations with a period of a few minutes. In addition, the results indicate that the eruption generates supersonic shock waves in the volcanic region, leading to the extremely large vertical oscillations in the thermosphere and ionosphere above the volcanic eruption region.

3D Traveling Ionospheric Disturbances During the 2022 Hunga Tonga–Hunga Ha’apai Eruption Using GNSS TEC

“…The results indicated that the highest electron density was at an altitude of ∼280-350 km, as presented in Figure 12, and this is in line with the 3D tomography modeling applied at the height of the third ionospheric layer with an altitude of ∼300 km (Chapman, 1931). The results obtained in this study are consistent with those in the study by Shinbori et al (2022), which indicated that the electron density calculated as a function of time had and Miyoshi (2023). This alignment provides crucial validation for radio occultation data, thereby enhancing and fortifying our comprehension of TIDs at elevated altitudes.…”

“…Furthermore, the adaptability of 3D tomography extends to observing the effects of SW and LW at altitudes of up to ∼500 km. These observations align seamlessly with data acquired through radio occultation methods, where TIDs can reach up to ∼500 km altitude, as reported by Shinagawa and Miyoshi (2023). This alignment provides crucial validation for radio occultation data, thereby enhancing and fortifying our comprehension of TIDs at elevated altitudes.…”

“…(b) We further analyzed the relationship between TIDs and tsunami height. (c) The effects of shock waves (SW) and LW up to ∼500 km altitude were observed using 3D tomography; these findings concur with data obtained from radio occultation methods, where TIDs can reach up to ∼500 km altitude (Shinagawa & Miyoshi, 2023). (d) Ionospheric disturbances resulting from HTHH eruptions in areas near the HTHH, especially in Australia and New Zealand, were examined using the previous research.…”

“…In New Zealand, the results of the analysis show that the first TID has a maximum concentration of oblique TEC changes at 200–300 km above the surface and begins to decrease at an altitude of 500–600 km. Shinagawa and Miyoshi (2023) also found that this TID can reach heights of up to ∼500 km using the radio occultation method. Additionally, our 3D model shows the direction of the TID to be the same as the direction of the tsunami and atmospheric waves (spreading outward).…”