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A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols

Publication ,  Journal Article
Kasibhatla, P; Chameides, WL; St. John, J
Published in: Journal of Geophysical Research Atmospheres
February 20, 1997

A global three-dimensional chemical transport model is used to investigate seasonal variations of anthropogenic sulfur in the troposphere. Particular emphasis is placed on detailed comparisons of the modeled surface sulfur dioxide (SQ2) and sulfate (SO4) concentrations and sulfate wet deposition fluxes with measurements from the Eulerian Model Evaluation Field Study (EMEFS) and Cooperative Program for Monitoring and Evaluation of the Long Range Transmission of Air Pollutants in Europe (EMEP) field programs in North America and Europe, respectively. Initial comparisons of model results with measurements reveal a systematic tendency of the model to overestimate SO2 concentrations and underestimate SO4 concentrations while producing a reasonable fit to measured wet deposition fluxes. Through a series of sensitivity tests we find that the addition of a nonphotochemical pathway for converting SO2 to SO4 in the boundary layer with a pseudo first-order rate of constant of 1-2 x 10-6S-1 provides the most reasonable method of bringing the model results into better agreement with the EMEFS and EMEP data sets. We propose that this additional pathway may be related to heterogeneous reactions between SO2 and atmospheric aerosols that typically are not included in models of the atmospheric sulfur cycle. Despite the vastly improved simulation of surface SO2 and SO4 when this hypothetical heterogeneous oxidation pathway is included, the model is unable to simultaneously simulate the large seasonal cycle in surface SO4 observed over eastern North America and the almost total absence of a seasonal cycle in surface SO4 over Europe. The seasonal cycles in model-predicted column SO4 burdens are similar, but not identical, to those for surface SO4 because of regional differences in transport, free tropospheric oxidation, and in-cloud removal. We find that the summer-to-winter ratio in column SO4 is larger over eastern North America than it is over Europe; however, both are larger than that for eastern Asia, where wintertime column SO4 is predicted to exceed summertime column SO4.

Duke Scholars

Published In

Journal of Geophysical Research Atmospheres

DOI

ISSN

0148-0227

Publication Date

February 20, 1997

Volume

102

Issue

3

Start / End Page

3737 / 3759

Related Subject Headings

  • Meteorology & Atmospheric Sciences
 

Citation

APA
Chicago
ICMJE
MLA
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Kasibhatla, P., Chameides, W. L., & St. John, J. (1997). A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols. Journal of Geophysical Research Atmospheres, 102(3), 3737–3759. https://doi.org/10.1029/96jd03084
Kasibhatla, P., W. L. Chameides, and J. St. John. “A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols.” Journal of Geophysical Research Atmospheres 102, no. 3 (February 20, 1997): 3737–59. https://doi.org/10.1029/96jd03084.
Kasibhatla P, Chameides WL, St. John J. A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols. Journal of Geophysical Research Atmospheres. 1997 Feb 20;102(3):3737–59.
Kasibhatla, P., et al. “A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols.” Journal of Geophysical Research Atmospheres, vol. 102, no. 3, Feb. 1997, pp. 3737–59. Scopus, doi:10.1029/96jd03084.
Kasibhatla P, Chameides WL, St. John J. A three-dimensional global model investigation of seasonal variations in the atmospheric burden of anthropogenic sulfate aerosols. Journal of Geophysical Research Atmospheres. 1997 Feb 20;102(3):3737–3759.

Published In

Journal of Geophysical Research Atmospheres

DOI

ISSN

0148-0227

Publication Date

February 20, 1997

Volume

102

Issue

3

Start / End Page

3737 / 3759

Related Subject Headings

  • Meteorology & Atmospheric Sciences