Effects of the May 2024 Solar Storm on the Earth's Radiation Belts Observed by CALET on the International Space Station
Year: 2026
Type: article
Abstract: In May 2024, extraordinary solar activity triggered a powerful solar storm, impacting Earth and producing the extreme geomagnetic storm of 10‐11 May, the most intense since 2003. This had significant effects on the magnetosphere, leading to the creation of a new long‐lasting component of relativistic electrons and to flux changes in the South‐Atlantic Anomaly. Here we present radiation‐belt observations made by the Calorimetric Electron Telescope (CALET) on the International Space Station. Specifically, we took advantage of the count rates from three layers of the CALET charge detector and imaging calorimeter. We show that the new electron storage ring extended to energies in the multi‐MeV range and down to McIlwain's L = 2.2, well below the nominal slot‐region barrier of L = 2.8, and persisted for several months, depending on energy. The evolution of the new radiation‐belt configuration over time was characterized by estimating the decay rates as a function of energy and L .
Source: Geophysical Research Letters
DOI: 10.1029/2025gl120032
Institutions: Louisiana State University, Goddard Space Flight Center, Heliophysics Science Division, Catholic University of America, University of Colorado Boulder, Laboratory for Atmospheric and Space Physics, National Aeronautics and Space Administration, Okinawa Institute of Science and Technology Graduate University, Shinshu University, Waseda University, Japan Aerospace Exploration Agency
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
OpenAlex ID: W7127960101