New upper limits for hydrogen halides on Saturn derived from Cassini-CIRS data

N. A. Teanby*, L. N. Fletcher, P. G. J. Irwin, T. Fouchet, G. S. Orton

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

9 Citations (Scopus)

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 3 sigma upper limits on HF, HCI, HBr, and HI volume mole fractions of 8.0 x 10(-12), 6.7 x 10(-11), 1.3 x 10(-10), and 1.4 x 10(-9), respectively, at the 500 mbar pressure level. These upper limits confirm sub-solar abundances of halide species for HF, HCI, and HBr in Saturn's upper atmosphere-consistent with predictions from thermochemical models and influx of material from meteoroids. Our upper limit for HCI is 16 times lower than the tentative detection at 1.1 x 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. (c) 2006 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)466-475
Number of pages10
JournalIcarus
Volume185
Issue number2
DOIs
Publication statusPublished - Dec 2006

Keywords

  • LINE PARAMETERS
  • PAIRS
  • ROTOTRANSLATIONAL ABSORPTION-SPECTRA
  • GIANT PLANETS
  • ATMOSPHERE
  • Saturn
  • TEMPERATURES
  • JUPITER
  • atmospheres
  • composition
  • HITRAN
  • PROBE MASS-SPECTROMETER
  • ISO-SWS OBSERVATIONS

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