%0 Journal Article %1 Moses2002a %A Moses, J. I. %A Zolotov, M. Y. %A Fegley, B. %D 2002 %J Icarus %K ATMOSPHERE; CHEMISTRY; CLOUD; GAS-PHASE; HUBBLE-SPACE-TELESCOPE; MODEL MONOXIDE; PELE PLUME; SO2 SODIUM SULFUR SURFACE SYMMETRICAL TRANSPORT; VERTICAL %N 1 %P 107--135 %T Alkali and chlorine photochemistry in a volcanically driven atmosphere on Io %V 156 %X Observations of the to plasma torus and neutral clouds indicate that the extended ionian atmosphere must contain sodium, potassium, and chlorine in atomic and/or molecular form. Models that consider sublimation of pure sulfur dioxide frost as the sole mechanism for generating an atmosphere on to cannot explain the presence of alkali and halogen species in the atmosphere-active volcanoes or surface sputtering must also be considered, or the alkali and halide species must be discharged along with the SO2 as the frost sublimates. To determine how volcanic outgassing can affect the chemistry of to's atmosphere, we have developed a one-dimensional photochemical model in which active volcanoes release a rich suite of S-, O-, Na-, K-, and Cl-bearing vapor and in which photolysis, chemical reactions, condensation, and vertical eddy and molecular diffusion affect the subsequent evolution of the volcanic gases. Observations of Pele plume constituents, along with thermochemical equilibrium calculations of the composition of volcanic gases exsolved from high-temperature silicate magmas on to, are used to constrain the composition of the volcanic vapor. We find that NaCl, Na, Cl, KCl, and K will be the dominant alkali and chlorine gases in atmospheres generated from Pele-like plume eruptions on to. Although the relative abundances of these species will depend on uncertain model parameters and initial conditions, these five species remain dominant for a wide variety of realistic conditions. Other sodium and chlorine molecules such as NaS, NaO, Na-2, NaS2, NaO2, NaOS, NaSO2, SCl, ClO, Cl-2, S2Cl, and SO2Cl2 will be only minor constituents in the ionian atmosphere because of their low volcanic emission rates and their efficient photochemical destruction mechanisms. Our modeling has implications for the general appearance, properties, and variability of the neutral sodium clouds and jets observed near to. The neutral NaCl molecules present at high altitudes in atmospheres generated by active volcanoes might provide the NaX+ ion needed to help explain the morphology of the high-velocity sodium "stream" feature observed near Io. (C) 2002 Elsevier Science (USA).

@article{Moses2002a, abstract = {Observations of the to plasma torus and neutral clouds indicate that the extended ionian atmosphere must contain sodium, potassium, and chlorine in atomic and/or molecular form. Models that consider sublimation of pure sulfur dioxide frost as the sole mechanism for generating an atmosphere on to cannot explain the presence of alkali and halogen species in the atmosphere-active volcanoes or surface sputtering must also be considered, or the alkali and halide species must be discharged along with the SO2 as the frost sublimates. To determine how volcanic outgassing can affect the chemistry of to's atmosphere, we have developed a one-dimensional photochemical model in which active volcanoes release a rich suite of S-, O-, Na-, K-, and Cl-bearing vapor and in which photolysis, chemical reactions, condensation, and vertical eddy and molecular diffusion affect the subsequent evolution of the volcanic gases. Observations of Pele plume constituents, along with thermochemical equilibrium calculations of the composition of volcanic gases exsolved from high-temperature silicate magmas on to, are used to constrain the composition of the volcanic vapor. We find that NaCl, Na, Cl, KCl, and K will be the dominant alkali and chlorine gases in atmospheres generated from Pele-like plume eruptions on to. Although the relative abundances of these species will depend on uncertain model parameters and initial conditions, these five species remain dominant for a wide variety of realistic conditions. Other sodium and chlorine molecules such as NaS, NaO, Na-2, NaS2, NaO2, NaOS, NaSO2, SCl, ClO, Cl-2, S2Cl, and SO2Cl2 will be only minor constituents in the ionian atmosphere because of their low volcanic emission rates and their efficient photochemical destruction mechanisms. Our modeling has implications for the general appearance, properties, and variability of the neutral sodium clouds and jets observed near to. The neutral NaCl molecules present at high altitudes in atmospheres generated by active volcanoes might provide the NaX+ ion needed to help explain the morphology of the high-velocity sodium "stream" feature observed near Io. (C) 2002 Elsevier Science (USA).}, added-at = {2009-11-03T20:21:25.000+0100}, author = {Moses, J. I. and Zolotov, M. Y. and Fegley, B.}, biburl = {https://www.bibsonomy.org/bibtex/2ba5bc865d41618f5e1f2753d013a3c61/svance}, interhash = {1ce7fab335c15ad7e7b47df9ce315a4f}, intrahash = {ba5bc865d41618f5e1f2753d013a3c61}, journal = {Icarus}, keywords = {ATMOSPHERE; CHEMISTRY; CLOUD; GAS-PHASE; HUBBLE-SPACE-TELESCOPE; MODEL MONOXIDE; PELE PLUME; SO2 SODIUM SULFUR SURFACE SYMMETRICAL TRANSPORT; VERTICAL}, number = 1, owner = {svance}, pages = {107--135}, timestamp = {2009-11-03T20:22:07.000+0100}, title = {Alkali and chlorine photochemistry in a volcanically driven atmosphere on Io}, volume = 156, year = 2002 }