2004/09/17 by Laura Schaefer, Bruce Fegley, Bruce Fegley Jr · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Atmospheric Ozone and Climate #Geological and Geochemical Analysis #astro-ph
paper · pdf · doi:10.1086/426113
published as Astrophys.J. 618 (2005) 1079-1085 · 21 pages, 4 figures, 4 tables; accepted by Astrophysical Journal
arxiv created 2004/09/17 · openalex publication_date 2005/01/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We use chemical equilibrium calculations to model the speciation of carbon in volcanic gases on Io. The calculations cover wide temperature (500-2000 K), pressure (10 -8 to 10 +2 bars), and composition ranges (bulk O/S atomic ratios ~0 to 3), which overlap the nominal conditions at Pele (1760 K, 0.01 bars, O/S ~ 1.5). Bulk C/S atomic ratios ranging from 10 -6 to 10 -1 in volcanic gases are used with a nominal value of 10 -3 based on upper limits from Voyager for carbon in the Loki plume on Io. Carbon monoxide and CO 2 are the two major carbon gases under all conditions studied. Carbonyl sulfide and CS 2 are orders of magnitude less abundant. Consideration of different loss processes (photolysis, condensation, kinetic reactions in the plume) indicates that photolysis is probably the major loss process for all gases. Both CO and CO 2 should be observable in volcanic plumes and in Io's atmosphere at abundances of several hundred parts per million by volume for a bulk C/S ratio of 10 -3 .