Statistical Distribution of Chorus Waves in Jupiter's Magnetosphere Based on Galileo and Juno Observations

Abstract

Whistler mode chorus waves are commonly observed in planetary magnetospheres and play an important role in the acceleration and loss of planetary energetic electrons. By combining the observations from Juno (PJ01 to PJ56) and Galileo, we conduct a detailed statistical analysis of the spatial distribution of the occurrence rates and averaged amplitudes of chorus waves in the Jovian magnetosphere. The statistical results show that chorus waves are widely distributed at 5 < M-shell < 15 within the magnetic latitudes (MLats) of < 50°, with the averaged amplitudes ranging from 3 to ∼50 pT. The most intense waves are found in the duskside inner magnetosphere at 8 < M-shell < 11 near the equatorial region (MLat < 20°). The wave amplitudes decrease significantly with increasing MLat, and are an order of magnitude larger on the duskside compared to the dawnside. Based on the statistical results, we develop an empirical model of the distribution of chorus wave amplitudes as a function of M-shell, magnetic local time and MLat, which can provide key information of the waves for future studies of resonant wave-particle interactions between chorus waves and energetic electrons at Jupiter.