In this work we present the detection of CH₄ and H₃⁺ emissions in the atmosphere of Jupiter as two well separated layers, located, respectively, at a tangent altitudes of about 200 km and 500-600 km above the 1-bar level. We studied the vertical distribution of the two species retrieving their Volume Mixing Ratio (VMR) and temperature simultaneously or allowing only one quantity to vary. From this analysis, it is not possible to firmly conclude if the observed H₃⁺ and CH₄ features are due to an increase of their VMR or rather to variations of the temperature of the two molecules. However, our retrieval indicates that CH₄ is in non-Local Thermal Equilibrium (non-LTE) condition, considering that the retrieved temperature values at about 300 km, where the maximum CH₄ concentration lies, is always about 100 K higher than the Galileo measurements.

We suggest that vertically propagating waves is the most likely explanation for the observed VMR and temperature variations in the JIRAM (Jovian InfraRed Auroral Mapper) data. Other possible phenomena could explain the observed evidences, for example a dynamical activity driving chemical species from lower layers towards the upper atmosphere, like the advection-diffusion processes responsible for the enhancement observed by Juno/MWR (MicroWave Radiometer), or soft electrons precipitation, although a better modeling is required to confirm these hypothesis.

The characterization of CH₄ and H₃⁺ species, simultaneously observed by JIRAM, offers the opportunity for better constraining the atmospheric models of Jupiter and understanding the planetary formation.