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| Titel |
Model Evaluations of Heterogeneous Nitryl Chloride Production |
| VerfasserIn |
Wayne Chang, Nicole Riemer |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090285
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| Publikation (Nr.) |
 EGU/EGU2014-4511.pdf |
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| Zusammenfassung |
| Nitryl chloride (ClNO2) is an important nighttime precursor to reactive chlorine radicals in
the troposphere. Recent ambient observations showed high correlations of ClNO2 and
N2O5mixing ratios, suggesting that the main production pathway of ClNO2 in the polluted
atmosphere is through N2O5heterogeneous hydrolysis on chloride-containing aerosols. Thus
in the presence of particulate chloride, N2O5heterogeneous hydrolysis can no longer be
considered a removal pathway for NOx, as ClNO2 is a reservoir species that can
release NO2 during the daytime through photolysis. Consequently, ClNO2 has high
potentials for altering the oxidative capacity of the atmosphere. There are many
challenges with quantifying the impact of ClNO2 through models, including the
parameterization of the N2O5heterogeneous reaction process, which is dependent on
meteorological conditions and aerosol compositions, the ClNO2 production yields, and
uncertainties with sources of particulate chloride. Using the WRF/Chem model as
the host model, we tested several state-of-the-art N2O5 heterogeneous hydrolysis
parameterizations, taking into account the uptake enhancement by the presence of particulate
chloride, and the uptake suppression by nitrate and organic coatings. The model results
are evaluated against observations made during the CalNex 2010 measurement
campaign. We will present the model performance in simulating ClNO2 by the various
parameterization methods, and show the sensitivity of ClNO2 production to spatial
and temporal variations in anthropogenic chlorine emission sources, as well as the
resulting impact on criteria pollutants in the South Coast Air Basin of California. |
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