The Relative Importance of Various Urban Sulfate Aerosol Production Mechanisms – A Theoretical Comparison

  1. David R. Schryer
  1. Paulette Middleton1,
  2. C. S. Kiang2 and
  3. Volker A. Mohnen3

Published Online: 21 MAR 2013

DOI: 10.1029/GM026p0221

Heterogeneous Atmospheric Chemistry

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

Author Information

  1. 1

    National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307

  2. 2

    School of Geophysical Sciences, Georgia Institute of Technology, Atlanta, Georgia 30322

  3. 3

    Atmospheric Science Research Center, State University of New York at Albany, Albany, New York 12222

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1982

ISBN Information

Print ISBN: 9780875900513

Online ISBN: 9781118663813

SEARCH

Keywords:

  • Atmospheric chemistry—Addresses, essays, lectures

Summary

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.