Simulation of ozone formation at different elevations in mountainous area of Hong Kong using WRF-CMAQ model

Wang, N.; Guo, Hai; Jiang, Fei; Ling, Zheng Hao; Wang, T.

doi:10.1016/j.scitotenv.2014.10.070

Cited by 101 publications

(53 citation statements)

References 40 publications

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“…Furthermore, it was not lower than 0.50 for primary air pollutants and reached 0.81 for O 3 simulation at both sites. The model performances were comparable to those reported in previous studies (Cabaraban et al, 2013;Wang et al, 2015). Therefore, we accepted the modeling results in view of the fact that the simulations were only used to qualitatively indicate the interactions between the continental and marine air in this study.…”

Section: Wrf-cmaq Simulation and Backward Particle Release Modelsupporting

confidence: 83%

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: Wrf-cmaq Simulation and Backward Particle Release Modelsupporting

confidence: 83%

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

et al. 2018

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“…The BL with (black line) and without (red line) the effects of BC are also presented in Figure 6. In general, ozone concentration is higher in upper layers before sunrise and in the early morning over polluted regions (Wang et al, 2015). When the BL develops, turbulence exchanges ozone in the vertical direction, resulting in entrainment of the abundant ozone aloft down to the surface (Figure 6a and b).…”

Section: Changes In Surface Ozone Resulting From Bc-bl Interaction 30mentioning

confidence: 98%

Effects of black carbon and boundary layer interaction on surface ozone in Nanjing, China

Zhu¹

2018

Preprint

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Abstract.As an important solar-radiation absorbing aerosol, the effect of black carbon (BC) on surface ozone, by influencing photolysis rate, has been widely discussed by "offline" model studies. However, BC-boundary layer (BL) 15 interactions also influence surface ozone. Using the "online" model simulations and processes analysis, we demonstrate the significant impact of BC-BL interaction on surface ozone. The absorbing effect of BC heats the air above the BL and suppresses BL development, which eventually leads to changes in the contributions of ozone through chemical and physical processes (photochemistry, vertical mixing, and advection). Different from previous "offline" model studies, BL suppression leads large amounts of ozone precursors being confined below the BL which offsetting the influence from the reduction of 20 photolysis rate, thus enhancing ozone photochemical formation before noon. Furthermore, the changes in physical process show a more significant influence on surface ozone. The weakened turbulence entrains much less ozone from the overlying ozone-rich air down to surface. As a result, the net contribution of ozone from physical and chemical processes leads to surface ozone reduction before noon. The maximum reduction reaches to 16.4 ppb at 12:00. In the afternoon, the changes in chemical process are small which influence inconspicuously to surface ozone. However, physical process still influences the 25 surface ozone significantly. Due to the delayed development of the BL, less vertically mixed BL continues to show an obvious ozone gradient near the top of the BL. Therefore, more ozone aloft can be entrained down to the surface, offsetting the surface ozone reduction. Comparing all the changes in the contributions of processes, the change in the contribution of vertical mixing plays a more important role in impacting surface ozone. Our results show the great impacts of BC-BL interactions on surface ozone. And more attention should be paid on the mechanism of aerosol-BL interactions when we deal 30 with the ozone pollution control in China.Atmos. Chem. Phys. Discuss., https://doi

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“…OH, HO 2 , RO, and RO 2 ), and intermediates. The model performance was evaluated using the index of agreement (IOA; Huang et al, 2005;Wang et al, 2015Wang et al, , 2013Lyu et al, 2015a):…”

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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Simulation of ozone formation at different elevations in mountainous area of Hong Kong using WRF-CMAQ model

Cited by 101 publications

References 40 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

Effects of black carbon and boundary layer interaction on surface ozone in Nanjing, China

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

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Simulation of ozone formation at different elevations in mountainous area of Hong Kong using WRF-CMAQ model

Cited by 101 publications

References 40 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

Effects of black carbon and boundary layer interaction on surface ozone in Nanjing, China

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

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