Revealing the Spatial Distribution of Dust and Plasma Solitary Waves in Jupiter's Innermost Magnetosphere Using Juno Waves Observations

Abstract

Jupiter's faint ring system contains micron- and submicron-sized dust whose dynamics are influenced by the planet's rapidly rotating magnetic field. Optical observations have established the morphology of the main ring and halo, but tenuous dust close to Jupiter remains difficult to characterize. We analyze nearly a decade of in-situ Juno Waves electric-field measurements using a two-stage convolutional neural network to identify and classify dust impacts, solitary waves, and other plasma waves. These in-situ dust-impact detections reveal a radially evolving structure extending well inside the traditionally observed halo. In the innermost region, dust is concentrated in a compact, equatorially symmetric layer, indicating that the optical inner boundary does not mark the end of the dust population. Farther outward, the layer expands vertically into a broad halo before contracting toward the main ring, directly revealing the toroidal morphology of the Jovian halo. Dust number density is enhanced within the halo and near the main-ring--halo transition. The vertical distribution also develops hemispheric asymmetries that vary with radial distance, consistent with an influence of Jupiter's magnetic geometry on charged-dust dynamics. In contrast, solitary waves occur predominantly at high latitudes, and their mapped magnetic footprints show a strong spatial correspondence with Jovian auroral structures, particularly the main auroral oval. Together, these in-situ measurements extend the remote-sensing picture of Jupiter's rings and reveal previously unresolved dust and plasma structures in its innermost magnetosphere.