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

Abstract

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