Wave signatures in the Jovian magnetosphere

Magnetometer data from the Ulysses Jupiter flyby are examined, in particular middle magnetosphere observations in the vicinity of the magnetodisk. Ion cyclotron waves are searched for in the heavy ion gyrofrequency regime (SO+2, SO+, K+, S+, Na+, O+ and S++). Power spectral peaks in the ion cyclotron frequency range from some of the dayside Ulysses magnetometer data have previously been described. Here we examine the dayside and high latitude duskside high resolution 1-s data. Ion cyclotron waves signatures are observed on several occasions both close to the magnetic equator and at some distance from it. Rippling and warping of the magnetodisk, as observed by Ulysses, could be the cause of such ion cyclotron signatures arising some distance away from the magnetic equator. Lower mass ions are observed further away from the planet and the heaviest mass ion signatures appear closer to the Io torus. Preliminary polarisation analysis of the observations is also presented and some theoretical implications of the wave signatures are discussed.