Search for the influence of the Galilean moons on Jovian kilometric and decametric radio emissions over 7 years of Juno data

The radio emissions generated at Jupiter by the Cyclotron Maser Instability (CMI) are categorized based on their frequency –kilometric, hectometric, or decametric; hectometric and decametric components are relatively continuous, see, e.g., Zarka et al. (2021)– and their origin, whether auroral or induced by the Galilean moons. Regarding the latter category, the moons Io, Europa, and Ganymede are known to influence Jupiter’s decametric radio spectrum. Emissions induced by Io have long been observed from Earth in the decametric range and were later confirmed down to the hectometric range by space missions. By contrast, radio signatures from Europa and Ganymede in the hectometric and decametric ranges have only been confirmed recently, through both ground–based and spacecraft observations. However, no clear evidence has yet been found of their influence in the kilometric range. In this study, we present an extended search for radio emissions induced by Europa, Ganymede, and Callisto, using seven years of Juno spacecraft observations. Io’s influence on the decametric radio emission is presented for the first time across the full [3.5–40] MHz range and from all latitudes. In the kilometric range, potential influence by the four different Galilean moons is observed for Io (in both hemispheres), Europa (Southern hemisphere), Ganymede (both hemispheres) and Callisto (both hemispheres).