Use of stable sulfur isotope systematics for evaluating oxidation reaction pathways and in-cloud-scavenging of sulfur dioxide in the atmosphere

Journal Article · Fri Jul 01 04:00:00 EDT 1994 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/94GL00893· OSTI ID:7031897

Tanaka, Noriyuki; Rye, D M; Xiao, Yitian; Lasaga, A C ^[1]

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1. Yale Univ., New Haven, CT (United States)

Sulfur dioxide injected into the atmosphere is most likely oxidized into sulfate. Two major oxidation pathways are possible: (1) a homogeneous pathway involving gas reaction with hydroxyl radicals and (2) a heterogeneous pathway involving aqueous dissolution or aerosol reactions. The relative importance of these reaction pathways conditions is controversial. Sulfur isotope ratios can be used to quantify the relative importance of these reaction pathways. However, its application was severely hampered by the fact that the isotope fractionation factor for the homogeneous pathway was not known. A significant isotope fractionation in the homogeneous SO[sub 2] oxidation is identified for the first time using an ab initio quantum mechanical calculation. By using the sulfur isotope fractionation factors the authors demonstrate a technique that uses measurements of the sulfur isotope ratio in gaseous SO[sub 2], aerosol SO[sub 4] and sulfate in wet precipitation to quantify the relative importance of the homogeneous and heterogeneous reaction pathways as well as the in-cloud scavenging of sulfur dioxide for a set of isotopic observations at New Haven, CT, USA. 15 refs., 1 fig., 2 tabs.

• DOE Contract Number: FG02-87ER60595; FG02-90ER14153
• OSTI ID: 7031897
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 21:14; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
CLOUDS
FRACTIONATION
HETEROGENEOUS CATALYSIS
HOMOGENEOUS CATALYSIS
ISOTOPE RATIO
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PRECIPITATION SCAVENGING
SEPARATION PROCESSES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
WASHOUT