Whistler‐Mode Waves and Associated Electron Distributions in Jupiter's Middle and Outer Magnetosphere

Whistler‐mode waves play a crucial role in shaping magnetospheric electron dynamics. Using Juno's observations, we investigate these waves in Jupiter's post‐midnight‐to‐dawn magnetosphere, spanning 20–80 Jupiter radii. Our survey reveals that whistler‐mode waves predominantly occur in the lobes, while the magnetodisk remains largely devoid of such waves. Simultaneous electron measurements from JADE‐E, combined with dispersion relation analysis, indicate that these waves are likely driven by a mono‐directional electron population between 0.1 and 10 keV propagating anti‐Jupiter‐ward. Further controlled studies show that a local flux minimum at 0.3 keV in the electron energy spectrum, which is commonly detected during whistler‐mode waves, is critical for wave growth. Based on their direction of motion, we suggest that these mono‐directional electrons and the whistler‐mode waves they generate are related to magnetosphere‐ionosphere coupling. Our findings offer new insights into the interplay between whistler‐mode waves and electrons in Jupiter's magnetosphere.