Precipitation Loss of Radiation Belt Electrons by Two‐Band Plasmaspheric Hiss Waves

Abstract

AbstractA two‐band plasmaspheric hiss consisting of a low‐frequency band (normal hiss with the frequency below 2 kHz) and a high‐frequency band (locally generated hiss with the frequency up to 10 kHz) was observed on 6 January 2014 by the Van Allen Probes (He et al., 2019, https://doi.org/10.1029/2018GL081578). The electron scattering effect driven by this kind of two‐band plasmaspheric hiss is evaluated by the quasi‐linear diffusion simulation for the first time. Realistic wave characteristic parameters of the two‐band plasmaspheric hiss from statistics are adopted for driving our simulation. The pitch angle diffusion rates of the low‐frequency band hiss present a “gap” with minimum magnitude at pitch angle αe ∼ 70°, a condition not favoring the transport of large pitch angle electrons toward the loss cone. However, the diffusion rates of the high‐frequency band hiss have peak values at αe ∼ 70°, filling up for the “gap” of the low‐frequency hiss diffusion rates. The realistic wave‐driven electron PSD evolutions demonstrate that the collaborated effect of the low‐frequency band and high‐frequency band hiss can cause significant precipitation losses of energetic electrons of tens to several hundred keV within 2 days.