Statistics of Whistler‐Mode Waves in the Near‐Earth Plasma Sheet

Abstract

AbstractElectromagnetic whistler‐mode waves are among the wave modes mainly responsible for energetic electron scattering and acceleration in the inner magnetosphere and near‐Earth plasma sheet. Although whistler‐driven electron precipitation significantly contributes to diffuse aurora at large L‐shells of ∼9–13, all existing empirical models of whistler‐mode waves are limited to the inner magnetosphere, at L < 9. This study aims to utilize more than 10 years of Time History of Events and Macroscale Interactions during Substorms observations to investigate main properties of whistler‐mode waves in the near‐Earth plasma sheet. We reveal relations between wave intensity and characteristics of the anisotropic electron population. We showed that in 99% of whistler wave events, the observed , mean wave frequency 〈f〉, and wave spectrum width Δf are consistent with expectations from the quasi‐linear theory of wave‐particle resonant interactions. Based on these statistics, we built an empirical model of , 〈f〉, and Δf as a function of L‐shell and MLT. This model extends existing inner magnetosphere models to a higher L‐shell range.