Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter - Update

摘要： An analysis of currently available ammonia (NH3) visible-to-near-infrared gas absorption data was recently undertaken by Irwin et al. (Icarus, 302 (2018) 426) to help interpret Very Large Telescope (VLT) MUSE observations of Jupiter from 0.48–0.93 μm, made in support of the NASA/Juno mission. Since this analysis a newly revised set of ammonia line data, covering the previously poorly constrained range 0.5–0.833 μm, has been released by the ExoMol project, “C2018” (Coles et al. 2018), which demonstrates significant advantages over previously available datasets, and providing for the first time complete line data for the previously poorly constrained 5520- and 6475-?A bands of NH3. In this paper we compare spectra calculated using the ExoMol–C2018 dataset (Coles et al. 2018) with spectra calculated from previous sources to demonstrate its advantages. We conclude that at the present time the ExoMol–C2018 dataset provides the most reliable ammonia absorption source for analysing low to medium resolution spectra of Jupiter in the visible/near-IR spectral range, but note that the data are less able to model high-resolution spectra owing to small, but significant inaccuracies in the line wavenumber estimates. This work is of significance not only for solar system planetary physics, but for future proposed observations of Jupiter-like planets orbiting other stars, such as with NASA’s planned Wide-Field Infrared Survey Telescope (WFIRST).