A New Electron and Proton Radiation Belt Identified by CIRBE/REPTile-2 Measurements After the Magnetic Super Storm of 10 May 2024

Abstract

Following the largest magnetic storm in 20 years (10 May 2024), REPTile-2 on NASA's CIRBE satellite identified two new radiation belts containing 1.3–5 MeV electrons around L = 2.5–3.5 and 6.8–20 MeV protons around L = 2. The region around L = 2.5–3.5 is usually devoid of relativistic electrons due to wave-particle interactions that scatter them into the atmosphere. However, these 1.3–5 MeV electrons in this new belt seemed unaffected until a magnetic storm on 28 June 2024, perturbed the region. The long-lasting nature of this new electron belt has physical implications for the dependence of electron wave-particle interactions on energy, plasma density, and magnetic field strength. The enhancement of protons around L = 2 exceeded an order of magnitude between 6.8 and 15 MeV forming a distinct new proton belt that appears even more stable. CIRBE, after a year of successful operation, malfunctioned 25 days before the super storm but returned to functionality 1 month after the storm, enabling these discoveries.