| Συγγραφείς: |
Wu, Ya‐Ze1 (AUTHOR), Zhou, Xu‐Zhi1 (AUTHOR) xzzhou@pku.edu.cn, Yin, Ze‐Fan1 (AUTHOR), Sun, Yixin1,2 (AUTHOR), Yue, Chao1 (AUTHOR), Zong, Qiugang1,2 (AUTHOR) |
| Περίληψη: |
Discrete energy bands of ion fluxes, typically organized in velocity with equal separations, have been frequently observed in Jupiter's magnetosphere either in association with Galilean moons or in regions far from their influence. Here, we focus on the latter type and propose that these bands are manifestations of bounce‐phase structuring, analogous to drift‐phase structuring responsible for the well‐known zebra‐stripe patterns. In our proposed framework, latitude‐dependent electric‐field perturbations interact with particles at different bounce phases, producing phase‐dependent energy modulations. As the particles continue to bounce at their respective bounce frequencies, which scale with velocity, these modulations naturally evolve into discrete, velocity‐ordered banded structures. We examine several potential sources of latitude‐dependent electric fields, including impulsive disturbances and wave‐related processes, and perform test‐particle simulations showing that the key observational features can be reproduced. These results support bounce‐phase structuring as a unifying interpretation of discrete bands, providing potential diagnostic perspectives on Jovian magnetospheric dynamics. Plain Language Summary: Jupiter has the largest and most powerful magnetic environment in the solar system. Spacecraft measurements have shown that ions within this environment sometimes form striking energy patterns, appearing as a series of discrete bands that are evenly spaced in velocity. These bands can occur near Jupiter's large moons, but they are also commonly observed far away from any moon. Until now, the origin of these non‐moon bands has remained unclear. In this study, we aim to understand how these non‐moon energy bands are formed. In Jupiter's magnetosphere, ions bounce back and forth along magnetic field lines, with the bounce frequency depending on velocity. When a latitude‐dependent electric field perturbation occurs, ions at different phases of their bounce motion are affected differently, leading to inhomogeneous ion distributions along the field lines. As the ions continue to bounce, these distributions naturally develop into a set of discrete energy bands organized by velocity. Numerical simulations show that this process can reproduce the patterns observed by NASA's Juno spacecraft. Our results suggest that both moon‐related and non‐moon energy bands can arise from the same underlying principle and provide a new way to remotely probe the electromagnetic dynamics inside Jupiter's magnetosphere. Key Points: Discrete ion energy bands at Jupiter's magnetosphere, either with or without moon influence, can be explained by bounce‐phase structuringLatitude‐dependent electric fields produce bounce‐phase‐dependent ion energy modulation, which naturally evolves into velocity‐ordered bandsTest‐particle simulations reproduce the key observational features and indicate the diagnostic potential of these banded structures [ABSTRACT FROM AUTHOR] |