Characteristics, sources, and reactions of nitrous acid during winter at an urban site in the Central Plains Economic Region in China
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Published:2020-06-16
Issue:11
Volume:20
Page:7087-7102
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ISSN:1680-7324
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Container-title:Atmospheric Chemistry and Physics
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language:en
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Short-container-title:Atmos. Chem. Phys.
Author:
Hao Qi,Jiang Nan,Zhang Ruiqin,Yang Liuming,Li Shengli
Abstract
Abstract. Nitrous acid (HONO) in the core city of the Central Plains Economic Region in China was measured using an ambient ion monitor from 9 to 31 January 2019.
Measurement time intervals were classified into the following periods in
accordance with the daily mean values of PM2.5: clean days (CDs),
polluted days (PDs), and severely polluted days (SPDs). The HONO
concentrations during CD, PD, and SPD periods were 1.2, 2.3, and 3.7 ppbv,
respectively. The contributions of the homogeneous reaction, heterogeneous
conversion, and direct emissions to HONO sources varied under different
pollution levels. The mean values of the net HONO production of the
homogeneous reaction (POH+NOnet) in CD,
PD, and SPD periods were 0.13, 0.26, and 0.56 ppbv h−1, respectively.
The average conversions of NO2 (CHONO) in CD, PD, and SPD periods
were 0.72×10-2, 0.64×10-2, and 1.54×10-2 h−1, respectively, indicating that the heterogeneous
conversion of NO2 was less important than the homogeneous reaction.
Furthermore, the net production of the homogeneous reaction may have been
the main factor in the increase of HONO under high-NOx conditions
(i.e., when the concentration of NO was higher than that of NO2) at
nighttime. Daytime HONO budget analysis showed that the mean values of the
unknown source (Punknown) during CD, PD, and SPD periods were 0.26,
0.40, and 1.83 ppbv h−1, respectively. The values of
POH+NOnet, CHONO, and Punknown
in the SPDs period were comparatively larger than those in other periods,
indicating that HONO participated in many reactions. The proportions of
nighttime HONO sources also changed during the entire sampling period.
Direct emissions and a heterogeneous reaction controlled HONO production in
the first half of the night and provided a contribution that is larger than that of
the homogeneous reaction. The proportion of homogenization gradually
increased in the second half of the night due to the steady increase in NO
concentrations. The hourly level of HONO abatement pathways, except for OH + HONO, was at least 0.22 ppbv h−1 in the SPDs period. The cumulative
frequency distribution of the HONOemission∕HONO ratio (less than
20 %) was approximately 77 %, which suggested that direct emission was
not important. The heterogeneous HONO production increased when the relative
humidity (RH) increased, but it decreased when RH increased further. The
average HONO∕NOx ratio (4.9 %) was more than twice the assumed
globally averaged value (2.0 %).
Funder
National Natural Science Foundation of China
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference70 articles.
1. Acker, K., Möller, D., Auel, R., Wieprecht, W., and Kalaß, D.:
Concentrations of nitrous acid, nitric acid, nitrite and nitrate in the gas
and aerosol phase at a site in the emission zone during ESCOMPTE 2001
experiment, Atmos. Res., 74, 507–524,
https://doi.org/10.1016/j.atmosres.2004.04.009, 2005. 2. Alicke, B., Platt, U., and Stutz, J.: Impact of nitrous acid photolysis on
the total hydroxyl radical budget during the Limitation of Oxidant
Production/Pianura Padana Produzione di Ozono study in Milan, J. Geophys.
Res., 107, 8196–8208, https://doi.org/10.1029/2000jd000075, 2002. 3. Alicke, B., Geyer, A., Hofzumahaus, A., and Holland, F.: OH formation by
HONO photolysis during the BERLIOZ experiment, J. Geophys. Res., 108, 8247–8264,
https://doi.org/10.1029/2001jd000579, 2003. 4. Ammann, M., Kalberer, M., Jost, D. T., Tobler, L., Rössler, E., Piguet,
D., Gäggeler, H. W., and Baltensperger, U.: Heterogeneous production of
nitrous acid on soot in polluted air masses, Nature, 395, 157–160,
https://doi.org/10.1038/25965, 1998. 5. An, J., Li, Y., Chen, Y., Li, J., Qu, Y., and Tang, Y.: Enhancements of
major aerosol components due to additional HONO sources in the North China
Plain and implications for visibility and haze, Adv. Atoms. Sci., 30, 57–66,
https://doi.org/10.1007/s00376-012-2016-9, 2012.
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