Ultra low frequencies phenomena in Jovian decametric radio emission

Abstract

System of periodic peaks is found in the power spectra of ULF flux oscillations of Jovian decametric emission, which is observed at fixed frequencies. This result could be interpreted in terms of an ionospheric Alfvén resonator near Jupiter. Standing Alfvén wave could explain the system of emission bands in the dynamic spectrum of decametric emission. The space period of such bands and the frequency of standing waves have been used to estimate electron number density in the low magnetosphere of Jupiter. The result is consistent with radio occultation data. Hence, the ULF modulation hypothesis appears validated. © ESO 2006.