|
|||||
|
|
New upper limits for hydrogen halides on Saturn derived from Cassini-CIRS data |
|
| Authors: | NA Teanby LN Fletcher T Fouchet GS Orton |
| Institution: | a Atmospheric, Oceanic & Planetary Physics, Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK b Observatoire de Paris, LESIA, Meudon, F-92195, France c Université Pierre et Marie Curie-Paris 6, UMR 8109, Paris, F-75005, France d CALTECH, Jet Propulsion Laboratory, MS 169-237, 4800 Oak Grove Dr., Pasadena, CA 91109, USA |
| Abstract: | Far infrared spectra (10-600 cm−1) 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 3σ upper limits on HF, HCl, HBr, and HI volume mole fractions of 8.0×10−12, 6.7×10−11, 1.3×10−10, and 1.4×10−9, 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 1.1×10−9 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: | Saturn Atmospheres composition |
| 本文献已被 ScienceDirect 等数据库收录！ | |