Traveling Ionospheric Disturbances of the 2022 Tonga Volcano Eruption Observed by Ground-based GNSS Receivers in Taiwan and Japan
On January 15, 2022, at 04:05 UTC, the Tonga volcano eruption triggered traveling ionospheric disturbances (TIDs) propagating all over the world. The rate of total electron content (rTEC) derived by GNSS (Global Navigation Satellite System) receiving stations has been employed to observe TIDs in Taiwan and Japan. Results show that the TIDs in Lamb modes can induce the eastward dynamo electric fields which then uplift the ionosphere, enhance the plasma instability, and significantly fluctuate rTECs. Doppler frequency shifts recorded by CW-HF (continuous wave-high frequency) Doppler sounding systems, which consist of 5 sounding frequencies and 9 receiving stations in Taiwan together with rTEC fluctuations are examined to have a better understanding on responses of the ionosphere to the Lamb waves induced by TIDs of the 2022 Tonga Volcano Eruption.