DOI: 10.1002/jgrd.50183
论文题名: Contribution of isotopologue self-shielding to sulfur mass-independent fractionation during sulfur dioxide photolysis
作者: Ono S. ; Whitehill A.R. ; Lyons J.R.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 5 起始页码: 2444
结束页码: 2454
语种: 英语
英文关键词: mass-independent fractionation
; MIF
; photolysis
; SO2
; sulfate aerosol
; sulfur isotope
Scopus关键词: Aerosols
; Experiments
; Fractionation
; Isotopes
; Light sources
; Photolysis
; Reactor shielding
; Shielding
; Sulfate minerals
; Sulfur
; Ultraviolet radiation
; Volcanoes
; Xenon
; Mass-independent fractionation
; MIF
; SO2
; Sulfate aerosols
; Sulfur isotope
; Sulfur dioxide
; aerosol composition
; fractionation
; isotopic analysis
; photochemistry
; photolysis
; sulfur dioxide
; volcanic aerosol
; volcanic eruption
; Plinia
英文摘要: Signatures of sulfur mass-independent fractionation (S-MIF) are observed for sulfur minerals in Archean rocks, and for modern stratospheric sulfate aerosols (SSA) deposited in polar ice. Ultraviolet light photolysis of SO 2 is thought to be the most likely source for these S-MIF signatures, although several hypotheses have been proposed for the underlying mechanism(s) of S-MIF production. Laboratory SO2 photolysis experiments are carried out with a flow-through photochemical reactor with a broadband (Xe arc lamp) light source at 0.1 to 5 mbar SO2 in 0.25 to 1 bar N 2 bath gas, in order to test the effect of SO2 pressure on the production of S-MIF. Elemental sulfur products yield high δ34S values up to 140 ‰, with δ33S/ δ34S of 0.59 ± 0.04 and Δ36S/ Δ33S ratios of -4.6 ± 1.3 with respect to initial SO2 . The magnitude of the isotope effect strongly depends on SO 2 partial pressure, with larger fractionations at higher SO 2 pressures, but saturates at an SO2 column density of 1018 molecules cm-2. The observed pressure dependence and δ33S/δ34S and Δ36S/ Δ33S ratios are consistent with model calculations based on synthesized SO2 isotopologue cross sections, suggesting a significant contribution of isotopologue self-shielding to S-MIF for high SO2 pressure (>0.1 mbar) experiments. Results of dual-cell experiments further support this conclusion. The measured isotopic patterns, in particular the Δ36S/Δ33S relationships, closely match those measured for modern SSA from explosive volcanic eruptions. These isotope systematics could be used to trace the chemistry of SSA after large Plinian volcanic eruptions. © 2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63873
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge MA, United States; Department of Earth and Space Sciences, UCLA, Los Angeles CA, United States
Recommended Citation:
Ono S.,Whitehill A.R.,Lyons J.R.. Contribution of isotopologue self-shielding to sulfur mass-independent fractionation during sulfur dioxide photolysis[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(5)