A modeling analysis of a heavy air pollution episode occurred in Beijing

Xu, An; Zhu, Tong; Wang, Z.; Li, C.; Wang, Y.

doi:10.5194/acp-7-3103-2007

Cited by 123 publications

(50 citation statements)

References 7 publications

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“…Figure 6 illustrates the 24-h backward trajectory of the surface air mass arriving in Beijing at 17:00, which suggests that the photochemically-aged plume was associated with moderate southwesterly flows (∼300 km per day). The influences of the southerly transported polluted air mass on the air quality in Beijing have been discussed in previous studies (e.g., An et al, 2007, Wang et al, 2010b. The point underlined in this case study is that the coupling of in-situ photochemical ozone production during midday and the transport of ozone plumes in the late afternoon could further impact the air quality, particularly in terms of the "8-h-mean" O 3 guideline (WHO, 2006).…”

Section: Case 1: 3 August 2008mentioning

confidence: 58%

“…Observations at a rural site showed that the monthly averaged daytime mixing ratio of O 3 for August 2008 was reduced by ∼20 %, as being compared with the same month of -2007(Wang et al, 2009b. However, comparing the observations in Beijing downtown for periods before and after the traffic control indicated an increase of 16 % in the mixing ratio of O 3 (Wang et al, 2010b).…”

Section: Introductionmentioning

confidence: 92%

“…The economic development has brought up the number of vehicles, factories, as well as power plants in the Beijing metropolitan area during the last two decades. As a result, Beijing has suffered from serious air pollution An et al, 2007). Being the host city of the 29th Summer Olympic Games, the Beijing government setup rather aggressive action plans to reduce the emissions of air pollutants in Beijing and its surrounding areas during the Olympic period.…”

Section: Introductionmentioning

confidence: 99%

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Photochemical production of ozone in Beijing during the 2008 Olympic Games

et al. 2011

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Abstract. As a part of the CAREBeijing-2008 campaign, observations of O 3 , oxides of nitrogen (NO x and NO y ), CO, and hydrocarbons (NMHCs) were carried out at the air quality observatory of the Peking University in Beijing, China during August 2008, including the period of the 29th Summer Olympic Games. The measurements were compared with those of the CAREBeijing-2006 campaign to evaluate the effectiveness of the air pollution control measures, which were conducted for improving the air quality in Beijing during the Olympics. The results indicate that significant reduction in the emissions of primary air pollutants had been achieved; the monthly averaged mixing ratios of NO x , NO y , CO, and NMHCs decreased by 42.2, 56.5, 27.8, and 49.7 %, respectively. In contrast to the primary pollutants, the averaged mixing ratio of O 3 increased by 42.2 %. Nevertheless, it was revealed that the ambient levels of total oxidant (O x = O 3 +NO 2 +1.5NO z ) and NO z were reduced by 21.3 and 77.4 %, respectively. The contradictions between O 3 and O x were further examined in two case studies. Ozone production rates of 30-70 ppbv h −1 and OPEx of ∼8 mole mole −1 were observed on a clear-sky day in spite of the reduced levels of precursors. In that case, it was found that the mixing ratio of O 3 increased with the increasing NO 2 /NO ratio, whereas the NO z mixing ratio leveled off when NO 2 /NO>8. Consequently, the ratio of O 3 to NO z increased to above 10, indicating the shift from VOC-sensitive regime to NO x -sensitive regime. However, in the other case, it was found that the O 3 production was inhibited significantly due to substantial reduction in the NMHCs. According to the observations, it was suggested that the O 3 and/or O x production rates in BeijingCorrespondence to: C. C.-K. Chou (ckchou@rcec.sinica.edu.tw) should have been reduced as a result of the reduction in the emissions of precursors during the Olympic period. However, the nighttime O 3 levels increased due to a decline in the NO-O 3 titration, and the midday O 3 peak levels were elevated because of the shift in the photochemical regime and the inhibition of NO z formation.

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Section: Case 1: 3 August 2008mentioning

confidence: 58%

Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

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Photochemical production of ozone in Beijing during the 2008 Olympic Games

et al. 2011

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“…Recently, An et al (2007) applied the CMAQ model to study a heavy particulate and sulfur episode observed in spring in Beijing by using emission switch on/off method, in his results, the contribution to the fine particles in Beijing was about 39 %∼53 % from the northwest (notably from Zhangjiakou), and 15 % from the southwest (notably from Baoding). Similarly, Streets et al (2007) reported that PM 2.5 concentrations from Shandong Province might reach a maximum contribution of 63 % to Beijing under certain Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Section: Introductionmentioning

confidence: 99%

A numerical study of contributions to air pollution in Beijing during CAREBeijing-2006

Wang

Gbaguidi

et al. 2011

Atmos. Chem. Phys.

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Abstract. An online air pollutant tagged module has been developed in the Nested Air Quality Prediction Model System (NAQPMS) to investigate the impact of local and regional sources on the air pollutants in Beijing during the Campaign of Air Quality Research in Beijing 2006(CAREBeijing-2006). The NAQPMS model shows high performance in simulating sulfur dioxide (SO 2 ), particulate matter (PM 10 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ) with overall better agreements with the observations at urban sites than rural areas. With the tagged module, the air pollutant contributions from local and regional sources to the surface layer (about 30 m) and the upper layer (about 1.1 km) in Beijing are differentiated and estimated. The air pollutants at the surface layer in Beijing are dominated by the contributions from local sources, accounting for 65 % of SO 2 , 75 % of PM 10 and nearly 90 % of NO 2 , respectively, comparatively, the 1.1 km layer has large source contributions from the surrounding regions (e.g., southern Beijing), accounting for more than 50 % of the SO 2 and PM 10 concentrations. County scale analysis is also performed and the results suggest that Tianjin is the dominant source of SO 2 in Pinggu County, and Langfang, Hebei is the most important regional contributor to PM 10 in Beijing. Moreover, the surrounding regions show larger impact on SO 2 , PM 10 and NO 2 in the eastern counties of Beijing (e.g., Pinggu, Tongzhou and Daxing) than those in western Beijing, which is likely due to the Beijing's semi-basin topography and the summer monsoon. Our results indicate that the efforts to control the air pollutants in Beijing should focus on controlling both local and regional emissions.

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“…Especially in the most economically vibrant and densely populated areas, such as the Yangtze River Delta (YRD) region, the Pearl River Delta (PRD) region and the Beijing-Tianjin-Hebei (BTH) area, severe O 3 pollution episodes have frequently occurred (Lam et al, 2005; T. J. An et al, 2007;Chan and Yao, 2008;Duan et al, 2008;Jiang et al, 2008;Zhang et al, 2008;Guo et al, 2009;Shao et al, 2009;Ma et al, 2012), and the background air pollutant concentrations have steadily increased (Chan and Yao, 2008;Zhang et al, 2008;Tang et al, 2009;Ma et al, 2012;Liu et al, 2013). Many studies on the O 3 pollution, including satellite data analyses, field experiments and model simulations, have been carried out over China in order to investigate the temporal and spatial characteristics of surface photochemical pollution (Lu and Wang, 2006; H. X.…”

Section: Introductionmentioning

confidence: 99%

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

et al. 2016

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Abstract. Severe high ozone (O 3 ) episodes usually have close relations to synoptic systems. A regional continuous O 3 pollution episode was detected over the Yangtze River Delta (YRD) region in China during 7-12 August 2013, in which the O 3 concentrations in more than half of the cities exceeded the national air quality standard. The maximum hourly concentration of O 3 reached 167.1 ppb. By means of the observational analysis and the numerical simulation, the characteristics and the essential impact factors of the typical regional O 3 pollution are comprehensively investigated. The observational analysis shows that the atmospheric subsidence dominated by the western Pacific subtropical high plays a crucial role in the formation of high-level O 3 . The favorable weather conditions, such as extremely high temperature, low relative humidity and weak wind speed, caused by the abnormally strong subtropical high are responsible for the trapping and the chemical production of O 3 in the boundary layer. In addition, when the YRD cities are at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause worse air quality. However, when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O 3 pollution. The integrated process rate (IPR) analysis incorporated in the Community Multi-scale Air Quality (CMAQ) model is applied to further illustrate the combined influence of subtropical high and typhoon system in this O 3 episode. The results show that the vertical diffusion (VDIF) and the gas-phase chemistry (CHEM) are two major contributors to O 3 formation. During the episode, the contributions of VDIF and CHEM to O 3 maintain the high values over the YRD region. On 10-12 August, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb h −1 in Shanghai and 19.76 ppb h −1 in Hangzhou. In contrast, the cities far away from the sea can hardly be affected by the periphery circulation of typhoon system. When the typhoon system significantly weakens the subtropical high, the contribution values of all individual processes decrease to a low level in all YRD cities. These results provide an insight for the O 3 pollution synthetically impacted by the western Pacific subtropical high and the tropical cyclone system.

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A modeling analysis of a heavy air pollution episode occurred in Beijing

Cited by 123 publications

References 7 publications

Photochemical production of ozone in Beijing during the 2008 Olympic Games

Photochemical production of ozone in Beijing during the 2008 Olympic Games

A numerical study of contributions to air pollution in Beijing during CAREBeijing-2006

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

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