A Jovian Decametric Emission Event Observed Locally by Juno and Remotely by Wind and STEREO-A at 1 au

Abstract Juno in situ observations provide insightful data on plasma, electric, and magnetic fields associated with Jovian decametric (DAM) emission, while remote-sensing observations offer broader spatial and temporal coverage. Combining both perspectives may help us understand the dynamic processes of DAM radiation. In this work, we present an Io-related DAM emission continued intermittently for at least 2 hr, observed by Juno in situ and remotely by Wind and STEREO-A. The Io-DAM emission evolved from three discrete narrow arcs to one mixed broad arc within 11 minutes in remote-sensing dynamic spectra. The source remained near a lead angle of 6° from the main Alfvén wing spot during the observation. Juno/JADE detected peaks in electron energy flux and an upward loss-cone distribution. Using a set of resonance circles, we estimate a maximum growth rate γ / ω c of 6.4 × 10 −4 , corresponding to electron energies of 0.2–10 keV and emission angles of 77°–88°. Meanwhile, we infer the properties of the source region of the event from the remote-sensing observations at 1 au. The inferred results on electron energy, emission angle, and source locations are consistent with the Juno in situ observations, suggesting the consistent properties of this Io-DAM event over 2 hr observational intervals. This consistency also reinforces the reliability of the remote sensing inversion method. Our work contributes to the establishment of long-term stereoscopic remote monitoring, addressing limitations in local observational coverage and enhancing our understanding of the dynamic processes of DAM emission.