Analysis of ionospheric disturbance induced by Tonga volcanic eruption on January 15, 2022 based on GPS TEC

On January 15, 2022, the Tonga undersea volcano in the South Pacific Ocean erupted violently, which was the largest volcanic eruption in the past 30 years and produced strong atmospheric fluctuations, providing a rare opportunity for the study of volcanic ionospheric disturbances. Ionospheric disturbances caused by volcanic eruptions are calculated using GPS data near volcanoes, New Zealand, Australia and China, and the characteristics of traveling ionospheric disturbances (TIDs) were analyzed in terms of waveform, frequency, propagation speed and space-time distribution. The ionosonde, sea level monitoring and atmospheric pressure monitoring data are used to further analyze the propagation characteristics of TIDs. The results indicate that the eruption of the Tonga volcano has caused three types of TID in its vicinity: New Zealand, Australia and China. The first type of TIDs were detected in the vicinity of the volcano in the east, west, south and north directions, with a propagation speed of approximately 617~972 m/s. This type of TIDs is highly likely caused by sound waves generated by volcanic eruptions. The Tonga volcanic eruption only causes the second type of TIDs in the east and west directions near the volcano, and its propagation speed is about 472 m/s and 418 m/s, which may be caused by acoustic gravity waves or mixed waves derived from sound waves. The formation mechanism of the second type of TIDs needs further study. The Tonga volcanic eruption triggered the third type of TIDs in New Zealand, Australia and China, with a propagation velocity of about 328~352 m/s. This type of TIDs is closely related to Lamb waves. © 2024 SinoMaps Press. All rights reserved.