Discussing the processes constraining the Jovian synchrotron radio emissionʹs features

Our recent analysis and understanding of the Jovian synchrotron radio emission with a radiation-belt model is presented. In this work, the electron population is determined by solving the Fokker–Planck diffusion equation and considering different physical processes. The results of the modeling are first compared to in situ particle data, brightness distributions, radio spectrum, and beaming curves to verify the simulated particle distributions. The dynamics of high-energy electrons in Jupiterʹs inner magnetosphere and their related radio emission are then examined. The results demonstrate that the Jovian moons set the extension and intensity of the synchrotron emissionʹs brightness distribution along the magnetic equator. Simulations show that moons and dust both control the transport toward the planet by significantly reducing the abundance of particles constrained to populate, near the equator and inside 1.8 Jovian radii, the innermost region of the magnetosphere. Due to interactions with dust and synchrotron mechanism, radiation-belt electrons are moved along field lines, between Metis (1.79 Jovian radii) and Amalthea (2.54 Jovian radii), toward high latitudes. The quantity of particles transported away from the equator is sufficient to produce measurable secondary radio emissions. Among all the phenomena acting in the inner magnetosphere, the moons (Amalthea and Thebe) are the primary moderator for the radiationʹs intensity at high latitudes. Moon losses also affect the characteristics of the total radio flux with longitude. The sweeping effect amplifies the 10-h modulation of the beaming curveʹs amplitude while energy resonances occurring near Amalthea and Thebe belong to phenomena adjusting it to the right level. Interactions with dust do not significantly constrain radio spectrum features. Resonances near Amalthea and Thebe are responsible for the Jovian radio spectrumʹs particular slope.