Electron Precipitation Driven by Whistler‐Mode Waves: Effects of Wave‐Packet Variability

Energetic electron scattering and precipitation driven by electromagnetic whistler‐mode waves are key processes controlling electron losses in the outer radiation belt and near‐Earth plasma sheet. Intense whistler‐mode waves can induce nonlinear resonant interactions, including phase trapping and phase bunching, which enable much faster precipitation than diffusive scattering by low‐amplitude waves. These nonlinear processes, however, are sensitive to wave coherence, and the influence of wave‐packet variability (resulting in loss of coherence) on precipitation efficiency remains insufficiently explored. In this study, we investigate a well‐characterized event of energetic electron precipitation observed by ELFIN at low altitudes in combination with near‐equator THEMIS observations of waves. Using test‐particle simulations driven by THEMIS wave measurements, we reproduce the observed energy range of precipitating electrons and directly quantify how wave‐packet variability alters resonant dynamics and loss rates. We find that although wave‐packet variability significantly perturbs nonlinear resonant dynamics, the net precipitation fluxes remain largely unchanged. We also discuss the implications of these findings for modeling intense precipitation events and for advancing theoretical descriptions of wave‐particle resonant interactions.