Dynamics of Proton Flux in the South Atlantic Anomaly During the Super Geomagnetic Storm in May 2024.

This study presents the short‐term dynamic changes in proton flux within the South Atlantic Anomaly (SAA), during a super geomagnetic storm in May 2024. By integrating proton observation data (≥35, ≥70, ≥140 MeV) from multiple National Oceanic and Atmospheric Administration and Meteorological Operational satellite programme satellites with a short‐time‐scale running average (3‐day), we improve spatial resolution and reduce the smoothing effects associated with long‐time‐scale averaging (∼1 month). The results reveal a rapid (∼20%) decline in proton flux within the SAA region during the main phase of the geomagnetic storm. After reaching its minimum, the proton flux in the SAA rapidly recovered during the recovery phase. Additionally, under the influence of solar proton events, a significant increase in high‐energy proton flux was observed during the recovery phase of the storm. Notably, we found a previously unidentified characteristic: a time delay of ∼2.5 days between the minimum proton flux in the SAA and the minimum Dst index (−412 nT). Plain Language Summary: This study examines how proton flux in the South Atlantic Anomaly (SAA) responded to a super geomagnetic storm in May 2024. By integrating data from multiple National Oceanic and Atmospheric Administration and Meteorological Operational satellite programme satellites and applying a short‐time‐scale running average method, we improved measurement detail and accuracy. During the main phase of the storm, proton flux levels in the SAA dropped rapidly (∼20%). Notably, although the proton flux rapidly recovered in the recovery phase, we observed a roughly 2.5‐day delay between the lowest proton flux level in the SAA and the storm's minimum Dst index. This delay reveals a previously unnoticed feature in the SAA's response to strong geomagnetic storms. Key Points: A multi‐satellite data fusion and short‐time‐scale averaging method enhanced data accuracy, revealing detailed South Atlantic Anomaly (SAA) responses to the stormThe proton flux in the SAA dropped sharply during the main phase of the May 2024 super geomagnetic storm and recovered quickly afterwardA delay of ∼2.5 days was observed between the minimum SAA proton flux and the minimum Dst index [ABSTRACT FROM AUTHOR]