Abstract This study investigated the response of the ionospheric electron temperature ( T e ) over Sanya to the super geomagnetic storm of May 2024. The observations, conducted with the Sanya Incoherent Scatter Radar (SYISR; 18.3°N, 109.6°E, dip latitude: 12.8°N) using a zenith‐directed uncoded long pulse, provided the T e from May 10 to 12, 2024. On May 11, the daytime (nighttime) T e at 400 km increased ∼40% (∼30%) relative to the quiet‐time reference, and a wave‐like variation of T e was also observed. On May 12, a unique T e increase occurred above ∼270 km, with the T e at 400 km increasing ∼90% relative to the quiet‐time reference and remaining increased for ∼7 hr. Further Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) simulations reproduced the observed T e relatively well under realistic geophysical conditions. The TIEGCM simulations indicated that the decrease in the ionospheric electron density, which was associated with the unique T e increase, was dominated by chemistry at ∼270–380 km, while E × B drifts and neutral winds contributed most successively at higher altitudes. The simulations also revealed that the relative contribution of the electron‐neutral cooling was comparable with that of the electron‐ion cooling at 400 km and 09:00 LT on May 12, when the unique T e increase mainly occurred.
Wang et al. (Sun,) studied this question.