Importance of NOx control for peak ozone reduction in the Pearl River Delta region

Li, Ying; Lau, Alexis K.H.; Fung, Jimmy Chi Hung; Zheng, Junyu; Liu, Shaw-Chen

doi:10.1002/jgrd.50659

Cited by 107 publications

(56 citation statements)

References 69 publications

(84 reference statements)

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“…The NO x limited ozone formation regime occurred on most days except in the morning, when high NO x levels were observed regardless of the HO x simulation scenarios. This is consistent with the recent modeling study for the Pearl River Delta region by Li et al (2013). Differences among the scenarios are not noticeable in the morning when NO is high but noticeable differences can be found in the afternoon, which may cause uncertainty in assessing the optimal level of NO x and VOC emission controls from a policy perspective.…”

Section: Implications Of the Uncertainty In Ho X Estimations In Assessupporting

confidence: 90%

“…H. Zhang et al, 2008;Lim et al, 2011;Cheng et al, 2010;Shao et al, 2009a, b;Xing et al, 2011). Recently, however, a modeling study by Li et al (2013) in the Pearl River Delta region in China demonstrated the time dependence of ozone production regimes. Specifically, with high NO x emissions in the morning the regional ozone production regime is categorized as VOC limited.…”

Section: Implications Of the Uncertainty In Ho X Estimations In Assesmentioning

confidence: 99%

See 1 more Smart Citation

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Kim

Lee³

et al. 2015

Atmos. Chem. Phys.

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Abstract. Rapid urbanization and economic development in East Asia in past decades has led to photochemical air pollution problems such as excess photochemical ozone and aerosol formation. Asian megacities such as Seoul, Tokyo, Shanghai, Guangzhou, and Beijing are surrounded by densely forested areas, and recent research has consistently demonstrated the importance of biogenic volatile organic compounds (VOCs) from vegetation in determining oxidation capacity in the suburban Asian megacity regions. Uncertainties in constraining tropospheric oxidation capacity, dominated by hydroxyl radical, undermine our ability to assess regional photochemical air pollution problems. We present an observational data set of CO, NO x , SO 2 , ozone, HONO, and VOCs (anthropogenic and biogenic) from Taehwa research forest (TRF) near the Seoul metropolitan area in early June 2012. The data show that TRF is influenced both by aged pollution and fresh biogenic volatile organic compound emissions. With the data set, we diagnose HO x (OH, HO 2 , and RO 2 ) distributions calculated using the University of Washington chemical box model (UWCM v2.1) with nearexplicit VOC oxidation mechanisms from MCM v3.2 (Master Chemical Mechanism). Uncertainty from unconstrained HONO sources and radical recycling processes highlighted in recent studies is examined using multiple model simulations with different model constraints. The results suggest that (1) different model simulation scenarios cause systematic differences in HO x distributions, especially OH levels (up to 2.5 times), and (2) radical destruction (HO 2 + HO 2 or HO 2 + RO 2 ) could be more efficient than radical recycling (RO 2 + NO), especially in the afternoon. Implications of the uncertainties in radical chemistry are discussed with respect to ozone-VOC-NO x sensitivity and VOC oxidation product formation rates. Overall, the NO x limited regime is assessed except for the morning hours (8 a.m. to 12 p.m. local standard time), but the degree of sensitivity can significantly vary depending on the model scenarios. The model results also suggest that RO 2 levels are positively correlated with oxygenated VOCs (OVOCs) production that is not routinely constrained by observations. These unconstrained OVOCs can cause higher-than-expected OH loss rates (missing OH reactivity) and secondary organic aerosol formation. The series of modeling experiments constrained by observations strongly urge observational constraint of the radical pool to enable precise understanding of regional photochemical pollution problems in the East Asian megacity region.

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Section: Implications Of the Uncertainty In Ho X Estimations In Assessupporting

confidence: 90%

Section: Implications Of the Uncertainty In Ho X Estimations In Assesmentioning

confidence: 99%

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Kim

Lee³

et al. 2015

Atmos. Chem. Phys.

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“…The second domain had a grid resolution of only 12 km, which was unable to reflect the highly-precise underlying ground information. For example, the effect of urban street canopy (trapping and sustaining high spatial gradients in primary pollutants such as NO) cannot be fully considered (Jiang et al, 2010;Li et al, 2013). For PM 2.5 , the simulated average was 32.5 μg/m 3 and the observed average was 47.7 μg/m 3 .…”

Section: Evaluation Of Model Performancementioning

confidence: 92%

“…However, additional opportunities exist for reducing NO x , VOCs and NH 3 emissions due to the lack/inadequacy of control policy. Besides, it is widely recognized that these primary emissions play important roles in the formation of secondary pollutants (Louie et al, 2005a;Louie et al, 2005b;Edgerton et al, 2008;Chan and Yao, 2008;Wang et al, 2011;Ling et al, 2013;Li et al, 2013;Wang et al, 2013). Hence, in this study we choose to assess air quality (PM 2.5 and O 3 ) responding to emission controls of NO x , VOCs and NH 3 based on the recent control policies in PRD region .…”

Section: Introductionmentioning

confidence: 98%

Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China

Wang

Lyu

Deng

et al. 2016

Science of The Total Environment

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“…Rapid industrialization and urbanization have caused widespread air pollution recently in China (see, e.g., De Smedt et al, 2010;Lu et al, 2011) and numerous studies have investigated the severe O 3 pollution, particularly in the Beijing-Tianjin-Hebei (BTH) region (e.g., Wang et al 2006;Lin et al, 2008;Tang et al, 2009;Xu et al, 2011), Yangtze River delta (YRD) region (e.g., Geng et al, 2009Geng et al, , 2011Tie et al, 2009Tie et al, , 2012, and Pearl River delta (PRD) region (e.g., Zhang et al, 2008;Wang et al, 2009Wang et al, , 2011Cheng et al, 2010;Li et al, 2013). For example, Wang et al (2006) have observed strong O 3 production in urban plumes from Beijing with a maximum O 3 concentration of 286 ppb.…”

Section: Introductionmentioning

confidence: 99%

Summertime ozone formation in Xi'an and surrounding areas, China

et al. 2016

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Abstract. In this study, the ozone (O 3 ) formation in China's northwest city of Xi'an and surrounding areas is investigated using the Weather Research and Forecasting atmospheric chemistry (WRF-Chem) model during the period from 22 to 24 August 2013, corresponding to a heavy air pollution episode with high concentrations of O 3 and PM 2.5 . The model generally performs well compared to measurements in simulating the surface temperature, relative humidity, and wind speed and direction, near-surface O 3 and PM 2.5 mass concentrations, and aerosol constituents. High aerosol concentrations in Xi'an and surrounding areas significantly decrease the photolysis frequencies and can reduce O 3 concentrations by more than 50 µg m −3 (around 25 ppb) on average. Sensitivity studies show that the O 3 production regime in Xi'an and surrounding areas is complicated, varying from NO x to VOC (volatile organic compound)-sensitive chemistry. The industrial emissions contribute the most to the O 3 concentrations compared to biogenic and other anthropogenic sources, but neither individual anthropogenic emission nor biogenic emission plays a dominant role in the O 3 formation. Under high O 3 and PM 2.5 concentrations, a 50 % reduction in all the anthropogenic emissions only decreases near-surface O 3 concentrations by about 14 % during daytime. The complicated O 3 production regime and high aerosol levels pose a challenge for O 3 control strategies in Xi'an and surrounding areas. Further investigation regarding O 3 control strategies will need to be performed, taking into consideration the rapid changes in anthropogenic emissions that are not reflected in the current emission inventories and the uncertainties in the meteorological field simulations.

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Importance of NOx control for peak ozone reduction in the Pearl River Delta region

Cited by 107 publications

References 69 publications

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China

Summertime ozone formation in Xi'an and surrounding areas, China

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