Jupiter’s magnetic field geometry and its relation with new decameter radiation events observed by Juno

Decametric radio emissions (DAM) originating in Jupiter’s polar aurorae ought to generate along magnetic field lines at the local electron gyrofrequency. The Io-related DAM have received particular attention since the 1980’s, and it is expected that the maximum frequency of these emissions is bounded by the maximum magnetic field strength near the footprint of the instantaneous Io Flux Tube. DAM have been observed from Earth and spacecraft flybys before Juno, limiting the observation geometry to equatorial latitudes. Since 2016, and thanks to Juno, we have been able to observe Io-related DAM from a wide range of latitudes, leading to the observation of a new DAM feature that we preliminarily called “butterfly”. We analyze the Waves data from May 2016 to June 2023 searching for these butterflies to catalog them and determine their relationship with Io and the Jovian magnetic field. Based on the observation geometries, we found that these events (~ 135) are Io-related, they are always observed when Juno is in southern latitudes, they last for ~5 hours and their maximum observed frequency is ~20 MHz. As Juno is spending more time in southern latitudes as the mission progresses, the observation of butterflies keeps increasing over the years. Here, we study the role of the dipolar magnetic field of the southern hemisphere of Jupiter in the generation and observation of the butterfly events.