Comparative study of the power transferred from satellite-magnetosphere interactions to auroral emissions

Io's interaction with the Jovian magnetosphere generates a power of about 1012 W which propagates as Alfven waves along the magnetic field lines and is partly transferred to electrons, resulting in intense auroral emissions. A recent study of the power transmission along the Io flux tube and of the electron acceleration at high latitudes showed that the power of the observed emissions is well explained by assuming filamentation of the Alfven waves in the torus and the acceleration of the electrons at high latitude. At Jupiter, UV footprints related to Europa and Ganymede have also been observed. At Saturn recent observations revealed a weak UV footprint of Enceladus. We apply the Io interaction model to the Europa and Enceladus interactions. We show that the Alfven wave filamentation leads to a precipitating electron power consistent with the power of the observed UV footprints.