Global Model of Chorus Waves and Electron Lifetime Derived From Juno Observations

Abstract

Gyroresonant wave-particle interactions with whistler mode chorus waves plays a dual role in the precipitating loss and acceleration of energetic electrons in Jovian magnetosphere, which plays fundamental role in both Jovian radiation belt dynamics and auroral emission. Knowledge of the chorus wave power as a function of multi-dimensional spatial location and their spectral distribution are critical inputs for Jovian radiation belt modeling. In this work we present a global, analytical model of the typical Jovian chorus waves (0.1fce<f<0.8fce) based on the measurements made by Juno spacecraft in orbits 1 through 45, with which the whole nightside sector is covered. The radial, latitudal and local time dependence of the chorus wave intensity are derived. Mean-squared and most-probable spectral distributions are also statistically in separated M-shell and magnetic latitude sectors. With the updated chorus wave model, the wave-particle interaction is further quantified in terms of pitch angle, energy and mixed diffusion coefficients. We present an estimation of electron loss rate due to pitch angle scattering and henceforth precipitating to Jovian atmosphere in the format of electron lifetime as a function of energy and M-shell.