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| Titel |
Model investigation of NO3 secondary organic aerosol (SOA) source and heterogeneous organic aerosol (OA) sink in the western United States |
| VerfasserIn |
J. L. Fry, K. Sackinger |
| 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. 18 ; Nr. 12, no. 18 (2012-09-28), S.8797-8811 |
| Datensatznummer |
250011479
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| Publikation (Nr.) |
 copernicus.org/acp-12-8797-2012.pdf |
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| Zusammenfassung |
| The relative importance of NO3-initiated source and heterogeneous sink
of organic aerosol in the western United States is investigated using the
WRF/Chem regional weather and chemistry model. The model is run for the four
individual months, representing the four seasons, of January, May, August,
and October, to produce hourly spatial maps of surface concentrations of
NO3, organic aerosol (OA), and reactive organic gases (ROG, a sum of
alkene species tracked in the lumped chemical mechanism employed). These
"baseline" simulations are used in conjunction with literature data on
secondary organic aerosol (SOA) mass yields, average organic aerosol
composition, and reactive uptake coefficients for NO3 on organic
surfaces to predict SOA source and OA heterogeneous loss rates due to
reactions initiated by NO3. We find both source and sink rates maximized
downwind of urban centers, therefore with a varying location that depends on
wind direction. Both source and sink terms are maximum in summer, and SOA
source dominates over OA loss by approximately three orders of magnitude,
with large day-to-day variability. The NO3 source of SOA (peak
production rates of 0.4–3.0 μg kg−1 h−1) is found to
be significantly larger than the heterogeneous sink of OA via NO3
surface reactions (peak loss rates of
0.5–8 × 10−4 μg kg−1 h−1). |
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