LAUSR

The ion density and velocity measured by the advanced ionospheric probe (AIP) onboard FORMOSAT‐5 (F5) and ion velocity meter (IVM) onboard FORMOSAT‐7/COSMIC‐2 (F7C2), and the electron density assimilated by the global ionospheric specification (GIS) are employed to study the ionospheric plasma structure and dynamics during the 10 May 2024 Mother's Day storm (Dst −412 nT). The F5/AIP and F7C2/IVM display a large‐scale hole over the magnetic equator in the Atlantic Ocean area (−10° to 25°N, −60° to 20°E) during the local midnight period, with the minimum ion density of 1.7 × 104 #/cm3 and 1.6 × 103 #/cm3, respectively. In the hole area, F5/AIP and F7C2/IVM reveal upward ion velocities at 720 km altitude and downward ones at 550 km altitude, respectively, while GIS profiles show that the electron density yields the lower peak at ∼440 km and upper peak at ∼760 km altitude. This suggests that the downward and upward ion velocities result in the double‐peak feature.