Ionosphere Responses Over Asian‐Australian and American Sectors to the 10–12 May 2024 Superstorm

Abstract This work analyzed the ionospheric disturbances over the Asian‐Australian and American sectors during the superstorm that started from ∼17 UT on 10 May 2024. During 17–22.5 UT, the equatorial ΔH recorded the positive and negative disturbances in American and Asian sectors due to the penetration electric fields (PEFs). The Total Electron Content (TEC) at American was enhanced for ∼9 hr within 50°S–40°N, while TEC at Asian‐Australian decreased for ∼3 hr within 10°S–25°N. The equatorward disturbance winds promptly propagated to middle and low latitudes after 1 hr of the storm onset in Asian sector and impeded the negative TEC induced by the westward PEFs. In the recovery phase, the repeated elevations of hmF2s were observed in two sectors under the multiple PEFs resulting from the interplanetary magnetic fields Bz south‐north turning before 12 UT on 11 May. After that, in the American sector the westward disturbance dynamo electric fields were remarkable, and induced the negative storm effects at low latitudes; while in Asian‐Australian sector, the TEC presented the negative storm in the Northern Hemisphere and positive storm in the Southern Hemisphere. In Asian sector, the middle negative TEC storm became positive after 14–24 UT on 11 May and then switched to negative, which firstly occurred in the eastern regions and spread to westward and equatorward. These longitude gradients might be caused by disturbance winds and O/N2. Besides, the positive storm reinforced in conjugated Australian sector when the positive TEC was observed in Asian sector, indicating the possible contribution of the reinforced plasmasphere refilling.