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| Titel |
An MCM modeling study of the effects of nitryl chloride (ClNO2) on oxidation, ozone production, and nitrogen oxide partitioning in polluted coastal regions |
| VerfasserIn |
Joel Thornton, Theran Riedel, Glenn Wolfe, Kenten Danas, Jessica Gilman, William Kuster, Joost de Gouw, Daniel Bon, Alexander Vlasenko, Shao-Meng Li, Eric Williams, Brian Lerner, Patrick Veres, James Roberts, John Holloway, Barry Lefer |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077104
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| Zusammenfassung |
| Nitryl chloride (ClNO2) is produced efficiently at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing particles. Levels of ClNO2 exceeding 1 ppbv have been measured in several field campaigns near polluted regions. ClNO2 is photolyzed during the day to liberate highly reactive chlorine atoms. We have incorporated ClNO2 production, photolysis, and subsequent chlorine atom reactions into a Master Chemical Mechanism (MCM version 3.2) model framework. Chlorine atom reactions with alkenes and alcohols, not presently part of the MCM, have also been added. Using observational constraints from the CalNex 2010 field study, we assess the dominant reactive sources and sinks of chlorine atoms over the course of a model day, and the impact of this radical source on HOx and NOx abundance and partitioning, VOC lifetimes, and ozone production. Relative to model runs excluding ClNO2 formation, the presence of ClNO2 increases OH, HO2, and RO2 by a factor of 2 in the morning with a 10 - 20% perturbation to the total primary HOx production rate. Consistent with these changes, the formation of acyl peroxy nitrates is increased by 50% in the morning, and gross ozone production is enhanced by 10 - 20% (equivalent to about 12 ppb) compared to a model without ClNO2 formation included. We also include a discussion of the impact of Cl-atom chemistry on VOC, and in particular, on possible chlorine-containing VOC oxidation products which might act both as tracers of Cl-atom chemistry and as Cl-atom sources via subsequent reaction with OH. |
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