Overview
- The Arase satellite captured the first continuous, direct record of the May 10–11, 2024 event shrinking the plasmasphere’s outer edge from about 44,000 km to roughly 9,600 km in nine hours.
- Recovery took more than four days—the longest since Arase began monitoring in 2017—due to a negative storm that depleted ionospheric electrons and choked off the supply of refill particles.
- The peer-reviewed findings, published November 20 in Earth, Planets and Space, combine Arase observations with ground-based GPS data to link ionospheric chemistry changes to delayed plasmasphere recovery.
- The G5 superstorm, the strongest in more than two decades, produced rare low-latitude auroras seen in places such as Japan, Mexico, southern Europe, Townsville and Florida.
- During the event, GPS accuracy degraded, radio links faltered, and some satellites experienced electrical or transmission issues, underscoring the need for better space-weather forecasting and engineering resilience.