Mapping of Hydrocarbons and H3+ Emissions at Jupiter's North Pole Using Galileo/NIMS Data

In this paper we report the mapping of H3+, C2H2 and CH4 as derived by an unexploited Galileo/NIMS dataset. As previously observed, hydrocarbons emissions appear to be located in the internal part of the auroral main oval, where CH4 3-µm vibrational band intensity ratios [Kim et al., 2015] suggest that non-thermal excitation mechanisms, such as auroral particle precipitation and/or Joule heating, are responsible for the observed emissions. Temperature estimation are in good agreement for the CH4 emitting region on the hot spot, while the values obtained for H3+ are lower in comparison with Cassini/VIMS and ground based data. C2H2 emission overlaps the CH4 one only at higher latitudes >75°N, indicating that different energetic particles are at work inside the main oval polar ward. CH4 is also found on the northern section of the main oval (135° < LON < 190°, 60° < LAT < 90°N). The present investigation results have implications on the Juno/JIRAM observation planning as well as on the codes that will be used to retrieve temperatures and densities of all the emitting species involved in the Jupiter auroral processes.