Competing mechanisms of radial and local diffusion in radiation belt electron dynamics during quiet-geomagnetic...

While previous investigations utilizing high-resolution satellite observations (e.g., Van Allen Probes) have elucidated the competition between radial diffusion and local wave-driven acceleration mechanisms during geomagnetic storms, the relative dominance of these processes under long geomagnetically quiet conditions (K_p = 2) remains poorly quantified. To address this gap, we utilize a three-dimensional radiation belt simulation model to resolve electron dynamics. Our study quantifies the comparative roles of radial diffusion and chorus wave-driven diffusion across long quiet time, incorporating two parameterized radial diffusion models and chorus wave diffusion coefficients. Simulations span electron energies of 300 keV-3 MeV and equatorial pitch angles of 30^°-90^°, reveal that radial diffusion is the dominant mechanism driving electron acceleration, particularly at lower L-shells and higher pitch angles, where flux peaks are more pronounced. Conversely, chorus wave-driven local diffusion primarily governs electron loss at lower pitch angles, while promoting acceleration at higher pitch angles. This study highlights the critical role of radial diffusion in shaping radiation belt electron dynamics during geomagnetic quiescence, with chorus waves playing a secondary but significant role. The findings underscore the need for improved parameterizations of radial diffusion models and provide a theoretical foundation for understanding the interactions between radiation belt electrons and space weather phenomena.