부산대학교 도서관

Electromagnetic ion cyclotron (EMIC) waves play an important role in relativistic electron losses in the radiation belts through diffusion via resonant wave‐particle interactions. We present a new approach for calculating bounce and drift‐averaged EMIC electron diffusion coefficients. We calculate bounce‐averaged diffusion coefficients, using quasi‐linear theory, for each individual Combined Release and Radiation Effects Satellite (CRRES) EMIC wave observation using fitted wave properties, the plasma density and the background magnetic field. These calculations are then combined into bounce‐averaged diffusion coefficients. The resulting coefficients therefore capture the combined effects of individual spectra and plasma properties as opposed to previous approaches that use average spectral and plasma properties, resulting in diffusion over a wider range of energies and pitch angles. These calculations, and their role in radiation belt simulations, are then compared against existing diffusion models. The new diffusion coefficients are found to significantly improve the agreement between the calculated decay of relativistic electrons and Van Allen Probes data. Plain Language Summary: In recent years there have been an increasing number of satellites operating in or traversing the Earth's radiation belts. These belts are composed of charged particles that are largely confined by the Earth's magnetic field, although waves can accelerate and scatter these particles. In the outer belt, electrons can be accelerated up to relativistic energies and pose a threat to satellites. Diffusion‐based models are used to simulate the electron population, incorporating the statistical effects of waves on the electrons. Electromagnetic ion cyclotron waves are of particular importance for the relativistic population, effectively scattering them into the atmosphere and removing them from the belts. Previous models of this interaction are based on average plasma and wave observations; however, these do not well represent the range of interactions possible. Here we take a new approach, considering each observation individually to determine their statistical effect. When included into diffusion models, this new approach significantly improves the modeling of the relativistic electron population. Key Points: Novel statistical EMIC diffusion coefficients are determined using simultaneous observations of the individual plasma and wave parametersThe new diffusion coefficients show that EMIC waves diffuse electrons over a wide range of energies and pitch anglesWhen included into 3‐D radiation belt simulations, the new diffusion coefficients significantly improve agreement with observations [ABSTRACT FROM AUTHOR]