Ionospheric disturbances over South America related to Tonga Volcanic Eruption

Abstract

On January 15, 2022, we observed various unusual atmospheric wave events over South America: Atmospheric pressure waves (Lamb mode) around 12:30 to 17:30 UT, tsunamis along the Chilean coast at around 17:00 to 19:00 UT, and ionospheric disturbances between 11:30 and 20:00 UT. We understand that these events were generated by the Tonga volcanic eruption that occurred at (20.55°S, 175.39°W) in South Pacific Ocean at 04:15 UT. Several traveling ionospheric disturbances (TIDs), the horizontal wavelengths of 330 to 1174 km and the phase speed of 275 to 544 m/s were observed before and after the Lamb wave passed over the continent and the arrival of the tsunami on the Chile coast. The observed TID characteristics suggest us that these waves might be generated above the mesosphere far from the observation site. This is the first time to report the signature of ionospheric disturbances over the South American continent generated by the huge volcanic eruption.

Extreme Horizontal Wind Perturbations in the Mesosphere and Lower Thermosphere Over South America Associated With the 2022 Hunga Eruption

“…The signal was notoriously homogeneous with height, suggesting a large vertical wavelength (≳40 km). Moreover, the observation of the largest TEC perturbations on the continent at ∼18 UT on January 15 (Takahashi et al., 2023) indicates that the signal may have covered a couple of hundred kilometers in altitude.…”

“…The eruption generated regionally localized perturbations as well. In South America, the strongest total electron content (TEC) variations on the day of the event were detected between around 17:00 and 22:00 UT (Takahashi et al., 2023). The onset time of these perturbations approximately coincides with the arrival time of the largest tsunami waves to the western coast of the continent (Carvajal et al., 2022).…”

Thermospheric Exospheric Temperature and Composition Responses on 15 January 2022 Tonga Volcanic Eruption Based on the Ionosonde Observations

“…The significant ionospheric disturbances resulted from this extreme eruption have been reported extensively using the multi‐instrument ionospheric observations, including ground‐based Global Navigation Satellite System total electron content, ionosonde and FORMOSAT‐7/COSMIC2 electron density profiles, Swarm plasma density, plasma velocity from the SuperDARN Hokkaido pair of radars, and the Ionospheric Connection Explorer (ICON) ion density (Aa, Zhang, Erickson, et al., 2022; Aa, Zhang, Wang, et al., 2022; Shinbori et al., 2022; Sun et al., 2022; Takahashi et al., 2023; Themens et al., 2022). The thermosphere and ionosphere are tightly coupled together, thus thermospheric parameters should have been highly disturbed.…”