Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1775508 | Icarus | 2006 | 10 Pages |
Abstract
Far infrared spectra (10-600 cmâ1) from Cassini's Composite InfraRed Spectrometer (CIRS) were used to determine improved upper limits of hydrogen halides HF, HCl, HBr, and HI in Saturn's atmosphere. Three observations, comprising a total of 3088 spectra, gave 3Ï upper limits on HF, HCl, HBr, and HI volume mole fractions of 8.0Ã10â12, 6.7Ã10â11, 1.3Ã10â10, and 1.4Ã10â9, respectively, at the 500 mbar pressure level. These upper limits confirm sub-solar abundances of halide species for HF, HCl, and HBr in Saturn's upper atmosphere-consistent with predictions from thermochemical models and influx of material from meteoroids. Our upper limit for HCl is 16 times lower than the tentative detection at 1.1Ã10â9 reported by Weisstein and Serabyn [Weisstein, E.W., Serabyn, E., 1996. Icarus 123, 23-36]. These observations are not sensitive to the deep halide abundance, which is expected to be enriched relative to the solar composition.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
N.A. Teanby, L.N. Fletcher, P.G.J. Irwin, T. Fouchet, G.S. Orton,