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| Titel |
Impacts of HONO sources on the photochemistry in Mexico City during the MCMA-2006/MILAGO Campaign |
| VerfasserIn |
G. Li, W. Lei, M. Zavala, R. Volkamer, S. Dusanter, P. Stevens, L. T. Molina |
| 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 ; 10, no. 14 ; Nr. 10, no. 14 (2010-07-16), S.6551-6567 |
| Datensatznummer |
250008636
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| Publikation (Nr.) |
 copernicus.org/acp-10-6551-2010.pdf |
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| Zusammenfassung |
| The contribution of HONO sources to the photochemistry in
Mexico City is investigated during the MCMA-2006/MILAGO Campaign using the
WRF-CHEM model. Besides the homogeneous reaction of NO with OH, four
additional HONO sources are considered in the WRF-CHEM model: secondary HONO
formation from NO2 heterogeneous reaction with semivolatile organics,
NO2 reaction with freshly emitted soot, NO2 heterogeneous reaction
on aerosol and ground surfaces. The WRF-CHEM model with the five HONO
sources performs reasonably well in tracking the observed diurnal variation
of HONO concentrations. The HONO sources included are found to significantly
improve the HOx (OH+HO2) simulations during daytime and the
partition of NO/NO2 in the morning. The HONO sources also accelerate
the accumulation of O3 concentrations in the morning by about 2 h
and subsequently result in a noticeable enhancement of O3
concentrations over the course of the day with a midday average of about 6 ppb.
Furthermore, these HONO sources play a very important role in the
formation of secondary aerosols in the morning. They substantially enhance
the secondary organic aerosol concentrations by a factor of 2 on average in
the morning, although they contribute less during the rest of the day. The
simulated particle-phase nitrate and ammonium are also substantially
enhanced in the morning when the four HONO sources are included, in good
agreement with the measurements. The impact of the HONO sources on the
sulfate aerosols is negligible because of the inefficient conversion of
H2SO4 from SO2 reacting with OH. |
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