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| Titel |
Low Levels of Nitryl Chloride in the Lower Fraser Valley of British Columbia |
| VerfasserIn |
Hans D. Osthoff, Charles A. Odame-Ankrah, Travis W. Tokarek, Youssef M. Taha, Corinne L. Schiller, Keith Jones, Roxanne Vingarzan |
| 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 |
250088400
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| Publikation (Nr.) |
 EGU/EGU2014-2500.pdf |
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| Zusammenfassung |
| It is well recognized that the Lower Fraser Valley (LFV) of British Columbia is prone to
episodes of poor air quality and exceedances of ozone (O3) and fine particulate matter
standards. Ainslie and Steyn (2007) have investigated 20 years of O3 air quality data in the
LFV region and deduced the existence of a "mystery [O3] precursor" which builds up prior to
exceedance days. One potential candidate for such a precursor is nitryl chloride (ClNO2),
which is formed at night from uptake of dinitrogen pentoxide (N2O5) on chloride containing
aerosol.
Here, we present a comprehensive measurement data set collected at a routine monitoring
site near the Abbotsford International Airport, which is located approximately 35 km from
the Pacific Ocean in the LFV, from July 20 to August 4, 2012. Measurements included the
nitrogen oxides NO, NO2, the peroxycarboxylic nitric anhyrides PAN and PPN, N2O5 and
ClNO2, NOy, O3, photolysis frequencies, selected volatile organic compounds
(VOCs), and submicron aerosol composition and size distributions. At night, O3 was
rapidly and often completely removed by titration (with nitric oxide of anthropogenic
origin and with unsaturated biogenic hydrocarbons) and by dry deposition in a
shallow nocturnal inversion surface layer. The low nocturnal O3 mixing ratios and
presence of strong sinks for NO3 limited the extent of nocturnal nitrogen oxide
chemistry at the measurement site. Consequently, mixing ratios of N2O5 and ClNO2
were low ( |
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