Prominent Ionospheric Responses Throughout the Multiple Different Altitudes From Bottomside to Topside Ionosphere in the Asian‐Australian Sector During the May 2024 Mother's Day Storm

Abstract Using data from multiple Low‐Earth‐Orbit (LEO) satellites, including Swarm‐A/B, TanDEM‐X (TDX), MetOp‐B/C, Defense Meteorological Satellite Project and Constellation Observing System for Meteorology, Ionosphere, and Climate‐2 (COSMIC‐2), we focused on the prominent ionospheric altitudinal responses in the Asian‐Australian sector during the May 2024 superstorm. During the minimum symmetric component of the ring current (SYM‐H) period from ∼22:00 UT on 10 May to ∼12:00 UT on 11 May, LEO‐based total electron content (TEC) revealed a prolonged and large‐scale daytime meridional enhancement, with maximum increases of 250%–450% and extending to above 800 km, likely driven by storm‐time neutral winds and disturbed electric fields. For the topside nighttime enhancement on 11 May in the northern Asian‐Australian sector, both enhanced H + /Ni and vertical drifts suggested that the plasmasphere refilling made major contributions. LEO‐based and ground‐based Global Navigation Satellite System (GNSS) TECs exhibited opposite responses in the southern Asian‐Australian region. Two distinct electron density profiles in the Australian and Indonesian regions were depicted, highlighting the differences linked to thermospheric compositions and dynamics/electrodynamics. These physical processes occurred throughout multiple different altitudes from bottomside to topside ionosphere, showing the severe impact of superstorms.