Atmospheric photochemical reactivity and ozone production at two sites in Hong Kong: Application of a Master Chemical Mechanism–photochemical box model

Ling, Zhenhao; Guo, Hai; Lam, S. H. M.; Saunders, S. M.; Wang, Tao

doi:10.1002/2014jd021794

Cited by 62 publications

(38 citation statements)

References 97 publications

(183 reference statements)

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“…In addition, the inherent uncertainty of NO x measurement mentioned above might slightly affect the modeling results. The PBM-MCM model has been successfully applied in previous studies (Cheng et al, 2010a;Lam et al, 2013;Ling et al, 2014). Details of the model construction can be found in Saunders et al (2003) and Lam et al (2013).…”

Section: Observation-based Modelmentioning

confidence: 99%

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

et al. 2018

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Abstract. Marine atmosphere is usually considered to be a clean environment, but this study indicates that the nearcoast waters of the South China Sea (SCS) suffer from even worse air quality than coastal cities. The analyses were based on concurrent field measurements of target air pollutants and meteorological parameters conducted at a suburban site (Tung Chung, TC) and a nearby marine site (Wan Shan, WS) from August to November 2013. The observations showed that the levels of primary air pollutants were significantly lower at WS than those at TC, while the ozone (O 3 ) value was greater at WS. Higher O 3 levels at WS were attributed to the weaker NO titration and higher O 3 production rate because of stronger oxidative capacity of the atmosphere. However, O 3 episodes were concurrently observed at both sites under certain meteorological conditions, such as tropical cyclones, continental anticyclones and sea-land breezes (SLBs). Driven by these synoptic systems and mesoscale recirculations, the interaction between continental and marine air masses profoundly changed the atmospheric composition and subsequently influenced the formation and redistribution of O 3 in the coastal areas. When continental air intruded into marine atmosphere, the O 3 pollution was magnified over the SCS, and the elevated O 3 (> 100 ppbv) could overspread the sea boundary layer ∼ 8 times the area of Hong Kong. In some cases, the exaggerated O 3 pollution over the SCS was recirculated to the coastal inshore by sea breeze, leading to aggravated O 3 pollution in coastal cities. The findings are applicable to similar mesoscale environments around the world where the maritime atmosphere is potentially influenced by severe continental air pollution.

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Section: Observation-based Modelmentioning

confidence: 99%

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

et al. 2018

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“…For a more detailed description of the MCM, see Jenkin et al (1997Jenkin et al ( , 2003 and . Some developments on localization of the MCM for Hong Kong and the addition of chemical reaction pathways of more biogenic VOC species and alkyl nitrates are given in our previous papers (Lam et al, 2013;Cheng et al, 2013;Ling et al, 2014;Lyu et al, 2015b (Lyu et al, 2016;Wang, 2003, 2004;Wang et al, 2005Wang et al, , 2009. TM is a rural site that is upwind of Hong Kong in autumn/winter seasons and HT is a background site at the southeastern tip of Hong Kong.…”

Section: Observation-based Modelmentioning

confidence: 99%

“…Values of radicals and intermediates are simulated by the OBM. Details of the calculation can be found in Ling et al (2014) and Xue et al (2014).…”

Section: Observation-based Modelmentioning

confidence: 99%

Long-term O<sub>3</sub>–precursor relationships in Hong Kong: field observation and model simulation

et al. 2017

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Abstract. Over the past 10 years (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014), ground-level O 3 in Hong Kong has consistently increased in all seasons except winter, despite the yearly reduction of its precursors, i.e. nitrogen oxides (NO x = NO + NO 2 ), total volatile organic compounds (TVOCs), and carbon monoxide (CO). To explain the contradictory phenomena, an observation-based box model (OBM) coupled with CB05 mechanism was applied in order to understand the influence of both locally produced O 3 and regional transport. The simulation of locally produced O 3 showed an increasing trend in spring, a decreasing trend in autumn, and no changes in summer and winter. The O 3 increase in spring was caused by the net effect of more rapid decrease in NO titration and unchanged TVOC reactivity despite decreased TVOC mixing ratios, while the decreased local O 3 formation in autumn was mainly due to the reduction of aromatic VOC mixing ratios and the TVOC reactivity and much slower decrease in NO titration. However, the decreased in situ O 3 formation in autumn was overridden by the regional contribution, resulting in elevated O 3 observations. Furthermore, the OBM-derived relative incremental reactivity indicated that the O 3 formation was VOClimited in all seasons, and that the long-term O 3 formation was more sensitive to VOCs and less to NO x and CO in the past 10 years. In addition, the OBM results found that the contributions of aromatics to O 3 formation decreased in all seasons of these years, particularly in autumn, probably due to the effective control of solvent-related sources. In contrast, the contributions of alkenes increased, suggesting a continuing need to reduce traffic emissions. The findings provide updated information on photochemical pollution and its impact in Hong Kong.

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“…The prevailing winds at TW were from the southeast. Detailed information about the two sites is given in Guo et al (2013) and Ling et al (2014Ling et al ( , 2016 .…”

Section: Site Description and Samplingmentioning

confidence: 99%

Modeling C₁–C₄ Alkyl Nitrate Photochemistry and Their Impacts on O₃ Production in Urban and Suburban Environments of Hong Kong

Lyu

Guo

Wang³

et al. 2017

JGR Atmospheres

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As intermediate products of photochemical reactions, alkyl nitrates (RONO2) regulate ozone (O3) formation. In this study, a photochemical box model incorporating master chemical mechanism well reproduced the observed RONO2 at an urban and a mountainous site, with index of agreement in the range of 0.66–0.73. The value 0.0003 was identified to be the most appropriate branching ratio for C1 RONO2, with the error less than 50%. Although levels of the parent hydrocarbons and nitric oxide (NO) were significantly higher at the urban site than the mountainous site, the production of C2–C3 RONO2 was comparable to or even lower than at the mountainous site, due to the lower concentrations of oxidative radicals in the urban environment. Based on the profiles of air pollutants at the mountainous site, the formation of C2–C4 RONO2 was limited by NOx (volatile organic compounds (VOCs)) when total volatile organic compounds (TVOCs)/NOx was higher (lower) than 10.0 ± 0.4 parts per billion by volume (ppbv)/ppbv. This dividing ratio decreased (p < 0.05) to 8.7 ± 0.4 ppbv/ppbv at the urban site, mainly due to the different air pollutant profiles at the two sites. For the formation of C1 RONO2, the NOx‐limited regime extended the ratio of TVOCs/NOx to as low as 2.4 ± 0.2 and 3.1 ± 0.1 ppbv/ppbv at the mountainous and urban site, respectively. RONO2 formation led to a decrease of simulated O3, with reduction efficiencies (O3 reduction/RONO2 production) of 4–5 parts per trillion by volume (pptv)/pptv at the mountainous site and 3–4 pptv/pptv at the urban site. On the other hand, the variations of simulated O3 induced by RONO2 degradation depended upon the regimes controlling O3 formation and the relative abundances of TVOCs and NOx.

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Atmospheric photochemical reactivity and ozone production at two sites in Hong Kong: Application of a Master Chemical Mechanism–photochemical box model

Cited by 62 publications

References 97 publications

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Long-term O<sub>3</sub>–precursor relationships in Hong Kong: field observation and model simulation

Modeling C₁–C₄ Alkyl Nitrate Photochemistry and Their Impacts on O₃ Production in Urban and Suburban Environments of Hong Kong

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Atmospheric photochemical reactivity and ozone production at two sites in Hong Kong: Application of a Master Chemical Mechanism–photochemical box model

Cited by 62 publications

References 97 publications

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Long-term O&lt;sub&gt;3&lt;/sub&gt;–precursor relationships in Hong Kong: field observation and model simulation

Modeling C1–C4 Alkyl Nitrate Photochemistry and Their Impacts on O3 Production in Urban and Suburban Environments of Hong Kong

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Resources

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Long-term O<sub>3</sub>–precursor relationships in Hong Kong: field observation and model simulation

Modeling C₁–C₄ Alkyl Nitrate Photochemistry and Their Impacts on O₃ Production in Urban and Suburban Environments of Hong Kong