Origin of intense plasma depletions after midnight over the Korean Peninsula during the geomagnetic storm on 11 May 2024

A band of total electron content (TEC) depletions of about 15 TEC unit passed over the Korean Peninsula after midnight during the geomagnetic storm on 11 May 2024. This magnitude of TEC depletions has not been previously reported in the region. We track the origin and evolution of these depletions using the TEC data from global navigation and satellite system network in Korea and Japan. A distinctive TEC depletion band, clearly visible even in TEC maps, emerges in the northern east of Japan. Its northwest-southeast alignment and westward movement are typical characteristics of traveling ionospheric disturbances (TID) in the region. The TEC depletions observed over the Korean Peninsula exhibit a similar band structure, and their appearance coincides with the arrival of the TID feature from Japan. This event provides evidence for the development of severe plasma depletions in association with TIDs.