Possible role of electromagnetic low frequency waves in the Io torus in the production of Jovian aurorae

The possible role of ULF waves observed in the Io torus in the genetation of Jovian aurorae is investigated. Auroral emissions have been observed, not only at high latitude, but also at the footprint of magnetic field connected to the Io torus in a limited longitudinal range around 150°. As Ulysses passed by Jupiter, it explored the Io torus in latitude and longitude, allowing to test a possible localozation of the waves on field lines mapping down into the aurora. A maximum intensity of the waves is observed in the high latitude part of the torus around the longitude where the aurorae were observed. Another maximum is also observed at the magnetic equator. The propagation mode of the waves is discussed and their amplitude is compared to the values necessary for scattering ions, showing that the ULF waves could possibly be at the origin of the aurorae.