资源环境科技发展态势分析平台

We present the average distribution of energetic electrons in Jupiter’s plasma sheet and outer radiation belt near the magnetic equator during Juno’s first 29 orbits. Juno observed a clear decrease of magnetic field amplitude and enhancement of energetic electron fluxes over 0.1–1000 keV energies when travelling through the plasma sheet. In the radiation belts, Juno observed pancake-shaped electron distributions with high fluxes at ∼90º pitch angle and whistler-mode waves. Our survey indicates that the statistical electron flux at each energy tends to increase from to . The equatorial pitch angle distributions are isotropic or field-aligned in the plasma sheet and gradually become pancake-shaped at . The electron phase space density gradients at MeV/G are relatively small at and become positive over , suggesting the dominant role of adiabatic radial transport at higher shells, and the possible loss processes at lower shells.