Detectability of HD and non-equilibrium species in the upper atmospheres of the giant planets from their submillimeter spectrum

Based on high spectral resolution observations from space, including Voyager IRIS spectra, the submillimeter spectra of Jupiter, Saturn, Uranus, and Neptune are modeled in the 10-200/cm range, and some frequencies and intensities of the rotation lines are derived from rotational constants and dipole moment values. It is suggested that the as-yet undetected molecules of HCP, H2S, H2Se, AsF3 (in Jupiter only), and the halides HF, HCl, HBr, and HI, could be observed in Jupiter and Saturn, while in Uranus and Neptune, PH3 and CO are found to be the only nonequilibrium species that could be detected. The detection of the R(0) line of HD in the four planets, and the R(1) line in Saturn, Uranus, and Neptune, makes possible in the determination of the D/H ratio for each planet. It is suggested that the HD lines on Uranus and Neptune will be observable by ISO, and that planetary submillimeter observations will be possible with the 8-m telescope of the ESA FIRST project.