The Relative Importance of Various Urban Sulfate Aerosol Production Mechanisms – A Theoretical Comparison
- David R. Schryer
Published Online: 21 MAR 2013
Copyright 1982 by the American Geophysical Union.
Heterogeneous Atmospheric Chemistry
How to Cite
Middleton, P., Kiang, C. S. and Mohnen, V. A. (1982) The Relative Importance of Various Urban Sulfate Aerosol Production Mechanisms – A Theoretical Comparison, in Heterogeneous Atmospheric Chemistry (ed D. R. Schryer), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM026p0221
- Published Online: 21 MAR 2013
- Published Print: 1 JAN 1982
Print ISBN: 9780875900513
Online ISBN: 9781118663813
- Atmospheric chemistry—Addresses, essays, lectures
Theoretical estimates have been made to demonstrate the relative importance of various pathways for the production of sulfate aerosols in an urban atmosphere away from the stationary sources under different atmospheric conditions. We have incorporated photochemical reactions, vapor condensation, and catalytic and noncatalytic oxidation on a wetted aerosol surface into our theoretical consideration. From our calculations it is found that under daytime conditions, with photochemical reactions, sulfuric acid vapor condensation and liquid-phase oxidation by H2O2 can be the dominant sulfate aerosol production mechanisms. Gas to particle conversion is expected to be an even more important pathway to sulfate aerosol formation under daytime conditions, since reactions involving radical clusters such as HSO3·H2O, HSO5·H2O, and SO3·H2O are approximated by H2SO4 condensation in our estimates. Under nighttime conditions, without photochemical reactions, sulfate aerosol production in general is lower than under daytime conditions, and catalytic and noncatalytic oxidation mechanisms on the wetted aerosols become important pathways for SO2-to-sulfate conversion.