Sporadic E responds to the 2022 Tonga volcano eruptions

In this study, we analyzed ionosonde observations in Eastern Asia to investigate the responses of the sporadic E (Es) layer to severe atmospheric disturbances caused by the Tonga volcanic eruptions on 15 January 2022. The most notable feature observed was the disappearance of the Es layer after approximately 10:00 UT, attributed to the vertical drift induced by the eruptions. The Es layer reappeared intermittently after 13:00 UT, coinciding with the arrival of the tropospheric Lamb wave. To understand the mechanism behind this intermittence, we also analyzed horizontal wind data in the mesosphere and lower thermosphere regions, recorded by meteor radars. Wind disturbances with periods of approximately 20 hours contributed to the nighttime formation of the Es layer on January 15.