Preliminary JIRAM results from Juno polar observations: 1. Methodology and analysis applied to the Jovian northern polar region

During the first orbit around Jupiter of the NASA/Juno mission, the Jovian Auroral Infrared Mapper (JIRAM) instrument observed the auroral regions with a large number of measurements. The measured spectra show both the emission of the H-3(+) ion and of methane in the 3-4 mu m spectral region. In this paper we describe the analysis method developed to retrieve temperature and column density (CD) of the H-3(+) ion from JIRAM spectra in the northern auroral region. The high spatial resolution of JIRAM shows an asymmetric aurora, with CD and temperature ovals not superimposed and not exactly located where models and previous observations suggested. On the main oval averaged H-3(+) CDs span between 1.8 x 10(12) cm(-2) and 2.8 x 10(12) cm(-2), while the retrieved temperatures show values between 800 and 950 K. JIRAM indicates a complex relationship among H-3(+) CDs and temperatures on the Jupiter northern aurora.