Test Particle Simulations of Dual‐Component Microbursts Observed by BARREL: Effects of Atmospheric Backscattering and Chorus Elements

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Abstract Electron microbursts are among the most important loss mechanisms for energetic electrons in the Earth's radiation belts and are often driven by wave‐particle interactions with discrete chorus wave elements. Observations from the Balloon Array for Radiation‐belt Relativistic Electron Losses (BARREL) mission have revealed microburst events with simultaneous burst and smooth precipitation components. We conduct numerical experiments for the reported events and identify the driving mechanisms for these dual‐component structures. A realistic atmospheric backscattering module based on Monte Carlo simulations is incorporated into test particle simulations of wave‐particle interactions to more accurately model electron precipitation. Using parameters constrained by BARREL observations, our simulations reproduce the observed dual‐component microbursts with similar burst‐to‐smooth ratios. Comparative runs show that energy dispersion in precipitation, driven by intense and discrete chorus elements, can naturally produce a smooth component alongside bursty precipitation. This indicates that the smooth component is an intrinsic feature of intense microbursts and contributes significantly to the total electron loss. We show that electron loss rates from microbursts are likely underestimated due to the neglect of these smooth components in observations with insufficient energy resolution. Although the backscattering module does not strongly affect the formation of the smooth component, it does reduce the peak precipitation rate and extends the overall duration of precipitation. These findings highlight the importance of incorporating realistic atmospheric backscattering into wave‐driven precipitation models to improve the accuracy of estimating electron precipitation.

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