Oxidant (O3 + NO2) production processes and formation regimes  in Beijing

Lu, K.; Wang, J.; Liu, S.C.; Zhu, T.; Su, H.; Zhang, Y.; Brauers, T.; Shao, M.; Hofzumahaus, A.; Wang, X.; Kita, K.; Chou, C.C.; Wahner, A.; Kondo, Y.

doi:10.1029/2009JD012714

Journal Article

Oxidant (O3 + NO2) production processes and formation regimes in Beijing

Lu, K. ; Zhang, Y. ; Su, H. ; Brauers, T.FZJ* ; Chou, C. C. ; Hofzumahaus, A.FZJ* ; Liu, S. C. ; Kita, K. ; Kondo, Y. ; Shao, M. ; Wahner, A.FZJ* ; Wang, J. ; Wang, X. ; Zhu, T.

2010
Union Washington, DC

Journal of Geophysical Research 115, 1 - 18 (2010) [10.1029/2009JD012714]

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Please use a persistent id in citations: http://hdl.handle.net/2128/20450 doi:10.1029/2009JD012714

Abstract: For CareBeijing-2006, two sites were established in urban and suburban regions of Beijing in summer 2006. Observations of O-3 and its precursors together with meteorological parameters at both sites are presented. Gross ozone production rate P(O-3) and sensitivity to nitric oxides (NOx) and volatile organic compounds (VOCs) were investigated using an observation-based photochemical box model (OBM). P(O-3) varied from nearly zero to 120 and 50 ppb h(-1) for urban and suburban sites, respectively. These rates were greater than the accumulation rates of the observed oxidant (O-3 + NO2) concentrations. The O-3 episodes typically appeared under southerly wind conditions with high P(O-3), especially at the urban site. Sensitivity studies with and without measured nitrous acid (HONO) as a model constraint suggested that the estimated P(O-3) at both sites was strongly enhanced by radical production from HONO photolysis. Both NOx- and VOC-sensitive chemistries existed over time scales from hours to days at the two sites. The variation in O-3-sensitive chemistry was relatively well explained by the ratio of the average daytime total VOC reactivity (k(TVOC)) to NO, with the transition chemistry corresponding to a k(TVOC)/NO value of 2-4 s(-1) ppb(-1). Pronounced diurnal variations in the O-3 production regime were found. In the morning, conditions were always strongly VOC-limited, while in the afternoon, conditions were variable for different days and different sites. The model-calculated results were tested by measurements of H2O2, HNO3, total OH reactivity, and HOx radicals. The OBM was generally capable of correctly simulating the levels of P(O-3), although it might tend to overpredict the VOC-sensitive chemistry.

Keyword(s): J

Classification:

Meteorology & Atmospheric Sciences

Note: This work was supported by the National Natural Science Foundation of China (no. 40675072), the Ministry of Science and Technology of China (2002CB410801), and the Beijing Council of Science and Technology (HB200504-6 and no. HB200504-2). The authors would like to thank the CareBeijing-2006 team, especially M. Hu, L. M. Zeng, Z. M. Chen, F. Holland, Y. F. Cheng, X. Li, and S. R. Lou, for technical help and support at the field sites and F. Rohrer for help in IDL programming. We are grateful to the anonymous reviewers for their helpful comments on the manuscript.

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