Speaker
Description
Jupiter is an intense source of Auroral Radio Emissions (AREs). Such emissions are produced by a resonance between non-relativistic electrons gyrating along Jupiter’s magnetic field lines and electromagnetic waves, known as the Cyclotron-maser instability. The Jovian AREs in the Decametric (DAM) wavelength range can be detected from ground-based radiotelescopes above the cut-off frequency of the Earth’s ionosphere. The occurrence of Jovian DAM is partially controlled by the Jovian satellites Io, Europa and Ganymede. The satellite control of the Jovian DAM consists of radio emissions induced by field-aligned electric currents resulting from the interaction between the satellites and the magnetospheric magnetic field along their orbit. An evidence of this control is the nonuniform occurrence of the jovian DAM emissions as a function of the satellites’ orbital phase and the observer’s longitude. Such evidence was firstly observed for Io and have been found also for Ganymede. The continuous observation of Jupiter’s radio emissions by the Nançay Decameter Array (NDA) along the years has enabled the gathering of an extensive digital data catalog with 29 years of daily observations. This catalog has already provided statistical evidences of control of the Jovian DAM emissions by Io and Ganymede, as well as the possibility of further selection and analysis of various jovian radio components. This work aimed at analyzing this NDA’s extended catalog to track any Jovian DAM emissions induced by the satellite Europa. We were able to detect 2 types of Europa DAM emissions, namely Eu-A and Eu-C (termed by analogy with the Io DAM reference). We have then identified their average parameters, such as the median, mean and standard deviation of the maximum frequency, duration and intensity.
