Ionospheric disturbances observed over Japan following the eruption of Hunga Tonga-Hunga Ha’apai on 15 January 2022

Abstract

Traveling ionospheric disturbances (TIDs) were observed over Japan by using Global Navigation Satellite System (GNSS) receiver network data after the eruption of Hunga Tonga-Hunga Ha’apai in Tonga on 15 January 2022. Two types of TIDs with different characteristics were observed as perturbation in the total electron content (TEC). The first one arrived at Japan which are located about 7800 km away from Hunga Tonga-Hunga Ha’apai about 3 h after the eruption. The amplitude was about ± 0.5 TECU. The wavefronts was in the NNE–SSW direction and propagated in the WNW direction (– 69$$^\circ$$ ∘ counter-clockwise from the north) at 250 m s$$^{-1}$$ - 1 . The wavelength was estimated as 400 km. The second one arrived at Japan about 7 h after the eruption. The amplitude was about ± 1.0 TECU. The wavefronts was in the NE–SW direction and propagated in the NW direction (– 53$$^\circ$$ ∘ counter-clockwise from the north) at 270 m s$$^{-1}$$ - 1 . The wavelength was longer than the first one and was estimated as 800 km. The first one were associated with ionospheric irregularities represented by the rate of TEC index (ROTI). In contrast, the second one did not have irregularities all over the TIDs, but in only a limited region. The arrival of the first TID was too early for the atmospheric acoustic waves to arrive, while the arrival of the second TIDs approximately coincided with the arrival of surface pressure enhancement. To understand the mechanisms of the TIDs, further studies with wide-area observations as well as numerical calculations are necessary. TIDs and ionospheric irregularities after volcanic eruption could be threats to GNSS-based systems especially for those which utilize carrier-phase measurements. Graphical Abstract

Response of the underground environment of the KAGRA observatory against the air-pressure disturbance from the Tonga volcano eruption on January 15th, 2022

“…The Lamb waves of the Earth's atmosphere are observed around 11:30 UTC and the atmospheric gravity wave at milli-Hz order is observed for a long time. This is consistent with other reports in Japan [12][13][14]. The small transient disturbances in the higher frequency bands that appeared before the arrival of the air-pressure wave signal are understood that be caused by human activities like opening/closing doors in the building.…”

“…3. A transient pressure disturbance of 2 Pa was observed in all barometers, consistent with many reports in Japan [12][13][14].…”

“…The impulsive shock wave caused by the volcanic eruption turned into long-period air-pressure waves and were observed worldwide. These waves also reached Japan, traveling longer than 8,000 km away from the Tonga volcano over the Pacific Ocean, and were observed as disturbances of the air-pressure [12][13][14]. These signals from the volcanic eruption were observed by the environmental sensors of KAGRA, not only outside the tunnel but also inside the underground facility.…”

Electromagnetic conjugacy of ionospheric disturbances after the 2022 Hunga Tonga-Hunga Ha’apai volcanic eruption as seen in GNSS-TEC and SuperDARN Hokkaido pair of radars observations

“…The air pressure waves caused tsunamis through the air-sea coupling process (Carvajal et al, 2022;Tanioka et al 2022). The atmospheric disturbances related to the violent eruption triggered atmospheric acoustic waves and AGWs (Adam 2022) that generate plasma density perturbations in the ionosphere (Astafyeva et al 2022;Lin et al 2022;Saito 2022;Themens et al 2022). Actually, various types of TID signatures globally appeared in two-dimensional maps of detrended TEC obtained from many GNSS stations for several days after the Hunga Tonga-Hunga Ha'apai volcanic eruption.…”

Multi-instrument detection in Europe of ionospheric disturbances caused by the 15 January 2022 eruption of the Hunga volcano

“…A volcanic eruption can produce waves of all these types, which will propagate outward from the eruption with different velocities and to different distances before dissipating. For this event, a Lamb wave was detected as the leading wavefront, followed by various disturbances of different natures (Burt, 2022;Kubota et al, 2022;Kulichkov et al, 2022;Saito, 2022). In this study, we look for disturbances in the ionosphere over Europe, close to the antipode of the eruption.…”