| 1 | Formation processes and source contributions of ground-level ozone in urban and suburban Beijing using the WRF-CMAQ modelling system显示文摘Beijing faces the challenge of high levels of ozone(O_(3))pollution.In this study,the Weather Research and Forecasting model and Community Multiscale Air Qualitymodel(CMAQ)were used to simulate atmospheric O_(3) concentrations in Beijing.To investigate the formation mechanisms and source contributions of O_(3) pollution in different regions of Beijing,process analysis and the integrated source apportionmentmethodwithin the CMAQwere applied to O_(3) concentrations in the summer of 2018.The process analysis results showed that vertical diffusion was the major contributor to O_(3) concentrations at all receptor sites in Beijing,at>65.94μg/(m^(3)·hr).Gas-phase chemical reactions consumed a significant amount of O_(3) in urban and inner suburban areas(>−5.57μg/(m^(3)·hr)),while near-surface chemical reactions made positive contributions in outer suburban areas(>4.72μg/(m^(3)·hr)).The O_(3) formation chemical reactions indicated that NO titration,which removes O_(3) at night-time,mainly occurred in urban areas.The weaker chemical reactions occurring near the surface in outer suburbs suggested that suburban-area O_(3) was produced in the upper atmospheric layers and was transported vertically to the lower layers.The O_(3) source apportionment results showed that boundary contributions were the dominant contributor to O_(3) pollution in Beijing(>40%).The contribution of non-local emissions to O_(3) levels was significantly greater in the outer suburbs than in urban and inner suburban areas due to topography.This study increases the understanding of the complex processes of O_(3) formation in different areas of Beijing and informs the implementation of O_(3) control plans. | Shuxian Zhang Zhongzhi Zhang Yang Li Xiaohui Du Linglu Qu Wei Tang Jun Xu Fan Meng | 2023 | Journal of Environmental Sciences2023，，5： | 1 |
| 2 | Comprehensive evaluation method of urban air quality statistics based on environmental monitoring data and its application显示文摘Air quality monitoring is effective for timely understanding of the current air quality status of a region or city.Currently,the huge volume of environmental monitoring data,which has reasonable real-time performance,provides strong support for in-depth analysis of air pollution characteristics and causes.However,in the era of big data,to meet current demands for fine management of the atmospheric environment,it is important to explore the characteristics and causes of air pollution from multiple aspects for comprehensive and scientific evaluation of air quality.This study reviewed and summarized air quality evaluation methods on the basis of environmental monitoring data statistics during the 13th Five-Year Plan period,and evaluated the level of air pollution in the Beijing-Tianjin-Hebei region and its surrounding areas(i.e.,the“2+26”region)during the period of the three-year action plan to fight air pollution.We suggest that air quality should be comprehensively,deeply,and scientifically evaluated from the aspects of air pollution characteristics,causes,and influences of meteorological conditions and anthropogenic emissions.It is also suggested that a threeyear moving average be introduced as one of the evaluation indexes of long-term change of pollutants.Additionally,both temporal and spatial differences should be considered when removing confounding meteorological factors. | Linglu Qu Fahe Chai Shijie Liu Jingchun Duan Fan Meng Miaomiao Cheng | 2023 | Journal of Environmental Sciences2023，，1： | 0 |
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