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| Titel |
Implementation of a Markov Chain Monte Carlo method to inorganic aerosol modeling of observations from the MCMA-2003 campaign – Part II: Model application to the CENICA, Pedregal and Santa Ana sites |
| VerfasserIn |
F. M. San Martini, E. J. Dunlea, R. Volkamer, T. B. Onasch, J. T. Jayne, M. R. Canagaratna, D. R. Worsnop, C. E. Kolb, J. H. Shorter, S. C. Herndon, M. S. Zahniser, D. Salcedo, K. Dzepina, J. L. Jimenez, J. M. Ortega, K. S. Johnson, G. J. McRae, L. T. Molina, M. J. 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 ; 6, no. 12 ; Nr. 6, no. 12 (2006-10-30), S.4889-4904 |
| Datensatznummer |
250004160
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| Publikation (Nr.) |
 copernicus.org/acp-6-4889-2006.pdf |
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| Zusammenfassung |
| A Markov Chain Monte Carlo model for integrating the observations of
inorganic species with a thermodynamic equilibrium model was presented in
Part I of this series. Using observations taken at three ground sites, i.e. a
residential, industrial and rural site, during the MCMA-2003 campaign in
Mexico City, the model is used to analyze the inorganic particle and ammonia
data and to predict gas phase concentrations of nitric and hydrochloric
acid. In general, the model is able to accurately predict the observed
inorganic particle concentrations at all three sites. The agreement between
the predicted and observed gas phase ammonia concentration is excellent. The
NOz concentration calculated from the NOy, NO and NO2
observations is of limited use in constraining the gas phase nitric acid
concentration given the large uncertainties in this measure of nitric acid
and additional reactive nitrogen species. Focusing on the acidic period of
9–11 April identified by Salcedo et al. (2006),
the model accurately predicts the particle phase observations during this
period with the exception of the nitrate predictions after 10:00 a.m. (Central Daylight Time, CDT)
on 9 April, where the model underpredicts the
observations by, on average, 20%. This period had a low planetary
boundary layer, very high particle concentrations, and higher than expected
nitrogen dioxide concentrations. For periods when the particle chloride
observations are consistently above the detection limit, the model is able
to both accurately predict the particle chloride mass concentrations and
provide well-constrained HCl (g) concentrations. The availability of
gas-phase ammonia observations helps constrain the predicted HCl (g)
concentrations. When the particles are aqueous, the most likely
concentrations of HCl (g) are in the sub-ppbv range. The most likely
predicted concentration of HCl (g) was found to reach concentrations of
order 10 ppbv if the particles are dry. Finally, the atmospheric relevance
of HCl (g) is discussed in terms of its indicator properties for the
possible influence of chlorine-mediated photochemistry in Mexico City. |
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