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Titel |
Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology |
VerfasserIn |
R. G. Stevens, J. R. Pierce, C. A. Brock, M. K. Reed, J. H. Crawford, J. S. Holloway, T. B. Ryerson, L. G. Huey, J. B. Nowak |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 1 ; Nr. 12, no. 1 (2012-01-03), S.189-206 |
Datensatznummer |
250010429
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Publikation (Nr.) |
copernicus.org/acp-12-189-2012.pdf |
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Zusammenfassung |
New-particle formation in the plumes of coal-fired power plants and other
anthropogenic sulfur sources may be an important source of particles in the
atmosphere. It remains unclear, however, how best to reproduce this
formation in global and regional aerosol models with grid-box lengths that
are 10s of kilometers and larger. The predictive power of these models is
thus limited by the resultant uncertainties in aerosol size distributions.
In this paper, we focus on sub-grid sulfate aerosol processes within
coal-fired power plant plumes: the sub-grid oxidation of SO2 with
condensation of H2SO4 onto newly-formed and pre-existing
particles. We have developed a modeling framework with aerosol microphysics
in the System for Atmospheric Modelling (SAM), a Large-Eddy
Simulation/Cloud-Resolving Model (LES/CRM). The model is evaluated against
aircraft observations of new-particle formation in two different power-plant
plumes and reproduces the major features of the observations. We show how
the downwind plume aerosols can be greatly modified by both meteorological
and background aerosol conditions. In general, new-particle formation and
growth is greatly reduced during polluted conditions due to the large
pre-existing aerosol surface area for H2SO4 condensation and
particle coagulation. The new-particle formation and growth rates are also a
strong function of the amount of sunlight and NOx since both control OH
concentrations. The results of this study highlight the importance for
improved sub-grid particle formation schemes in regional and global aerosol
models. |
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