LEO‐DOS Absorbed Dose Observations During the May 2024 Geomagnetic Superstorm

Abstract The Low‐Earth Orbit Space Radiation Dosimeter (LEO‐DOS) onboard Next‐Generation Satellite II (NEXTSat‐2) measured absorbed dose rate variations during the May 2024 geomagnetic superstorm. The observations show deep storm‐time penetration of solar energetic particle (SEP) spanning L ≈ 2–10, a pronounced enhancement near L ≈ 3 consistent with storm‐related electron belt formation, and a rapid decrease in inner‐belt proton dose rates near L ≈ 2 following storm onset. L‐shell‐resolved profiles, geographic dose rate maps, and the dose‐to‐flux (D/F) ratio collectively track the temporal evolution of source‐dependent contributions throughout the event. The superstorm drove a sustained and global reorganization of the LEO radiation environment, with deep SEP access, enhanced outer‐belt electrons, and rapid inner belt proton loss occurring nearly simultaneously. Because absorbed dose rate directly reflects energy deposition in shielding and tissue‐equivalent materials, LEO‐DOS measurements complement flux‐based analyses and enable a radiation‐hazard‐oriented interpretation of storm‐time belt restructuring.