Oscillations of the Ionosphere Caused by the 2022 Tonga Volcanic Eruption Observed With SuperDARN Radars. Issue 20 (19th October 2022)

• Record Type: Journal Article
• Authors: Zhang, Jiaojiao; Xu, Jiyao; Wang, Wei; Wang, Guojun; Ruohoniemi, J. Michael; Shinbori, Atsuki; Nishitani, Nozomu; Wang, Chi; Deng, Xiang; Lan, Ailan; Yan, Jingye
• Is Part Of: Geophysical research letters. Volume 49:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-19
• Subjects: ionospheric oscillation -- Tonga volcanic eruption -- SuperDARN radars; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2022GL100555
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: On 15 January 2022, the submarine volcano on the southwest Pacific island of Tonga violently erupted. Thus far, the ionospheric oscillation features caused by the volcanic eruption have not been identified. Here, observations from the Super Dual Auroral Radar Network radars and digisondes were employed to analyze ionospheric oscillations in the Northern Hemisphere caused by the volcanic eruption in Tonga. Due to the magnetic field conjugate effect, the ionospheric oscillations were observed much earlier than the arrival of surface air pressure waves, and the maximum negative line‐of‐sight (LOS) velocity of the ionospheric oscillations exceeded 100 m/s in the F layer. After the surface air pressure waves arrived, the maximum LOS velocity in the E layer approached 150 m/s. A maximum upward displacement of 100 km was observed in the ionosphere. This work provides a new perspective for understanding the strong ionospheric oscillation caused by geological hazards observed on Earth. Plain Language Summary: On 15 January 2022, an underwater volcano on the southwest Pacific island of Tonga erupted, triggering significant disturbances on the surface and in the ionosphere that propagated worldwide. The oscillation features of the ionosphere caused by the volcanic eruption have not been identified. The volcanic eruption caused numerous irregularities in the ionosphere. These irregularities move with the ionosphere similar to how leaves move in a rough sea. In this study, the ionospheric irregularities were observed and employed as tracers to analyze the ionospheric oscillations. Different features of ionospheric oscillations, including the maximum line‐of‐sight (LOS) velocity, the altitude of the maximum LOS velocity, and the propagation direction, were observed before and after the arrival of the surface air pressure waves. The amplitudes of the LOS velocities of the ionospheric fluctuations approached 150 m/s, and a maximum upward displacement of 100 km, which is the strongest ionospheric fluctuation caused by geological hazards ever observed. Key Points: Enhanced ionospheric irregularities with highly variable velocities were observed after the Tonga volcanic eruption The maximum amplitude of the line‐of‐sight velocity of the ionospheric oscillation approached 150 m/s in E layer The ionosphere was displaced upward by as much as 100 km