DOI: 10.1016/j.atmosenv.2020.117392
论文题名: Summertime ozone pollution in Sichuan Basin, China: Meteorological conditions, sources and process analysis
作者: Yang X. ; Wu K. ; Wang H. ; Liu Y. ; Gu S. ; Lu Y. ; Zhang X. ; Hu Y. ; Ou Y. ; Wang S. ; Wang Z.
刊名: Atmospheric Environment
ISSN: 1352-2310
出版年: 2020
卷: 226 语种: 英语
英文关键词: Air quality
; Chemical analysis
; Factorization
; Photochemical forming
; Volatile organic compounds
; Weather forecasting
; Community multi-scale air qualities
; Formation and evolutions
; Meteorological condition
; Ozone pollution
; Positive Matrix Factorization
; Regional transport
; Sichuan Basin
; Weather research and forecasting
; Ozone
; alkene
; ozone
; volatile organic compound
; air quality
; complex terrain
; ozone
; petrochemical industry
; pollutant transport
; relative humidity
; simulation
; solar radiation
; solvent
; terrain
; vertical mixing
; air pollutant
; Article
; China
; circadian rhythm
; concentration (parameter)
; controlled study
; environmental temperature
; high temperature
; humidity
; meteorological phenomena
; oxygen transport
; petrochemical industry
; priority journal
; solar radiation
; time series analysis
; wind speed
; China
; Sichuan Basin
学科: Air quality
; Ozone pollution
; Regional transport
; Sichuan basin
中文摘要: The Sichuan Basin (SCB) has suffered from serious ozone (O3) pollution in recent years, especially in summer. However, the formation and evolution mechanisms of O3 pollution in the SCB remain poorly understood. In this paper, we comprehensively investigated the causes of elevated ozone concentrations in Chengdu in July 2017 with a combination of field measurements and the WRF (Weather Research and Forecasting)-CMAQ (Community Multi-scale Air Quality) model simulations. The ozone formation characteristics of continuous O3 episodes and non-O3 episodes were compared. Higher temperature (T), stronger solar radiation (SR), lower relative humidity (RH) and weaker winds were conducive to O3 formation during ozone episodes. The O3 concentration during O3 episodes (202.6 μg m−3) was significantly higher than that during non-O3 episodes (122.7 μg m−3), attributable to the higher volatile organic compounds (VOCs) concentration (34.0 ppbv compared with 27.5 ppbv) despite comparable NOx concentrations during O3 episodes. The results of positive matrix factorization (PMF) for ambient VOCs showed that gasoline vehicle exhaust and solvent usage were the dominant sources during the month. However, the increasing source attributions from the petrochemical industry and biogenic emissions were responsible for the elevated VOCs concentrations during O3 episodes. The relative contributions of local emission and regional transport to ozone were quantified during two O3 episodes by conducting numerical sensitivity experiments. In the first episode, namely, the “O3-regionally transported” pattern, high ozone concentration in Chengdu was primarily due to the regional transport of ozone and ozone precursors through vertical mixing and horizontal advection from upwind areas (central and eastern SCB) when easterly or southeasterly winds prevailed over the SCB. In contrast, in the second episode, namely, the “O3-locally dominated” pattern, high local emissions under favorable meteorological conditions are the major reason for elevated ozone concentration. The process analysis results from the CMAQ model suggested that the vertical transport of O3 that formed at the upper levels from intense gas-phase chemistry reactions was a dominant contributor to diurnal O3 enhancement in O3 episodes by 45 μg m−3, while horizontal transport contributed more than 80% of the nocturnal O3 concentration. This study provides a better understanding of ozone photochemical formation and regional transport mechanisms in the SCB under complex terrain conditions, and contributes to ozone pollution prevention in other basins around the world. © 2020 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160414
Appears in Collections: 气候变化与战略
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作者单位: Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu, China; Department of Land, Air, and Water Resources, University of California, DavisCA, United States; School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai, Guangdong, China; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong; Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, United States; Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China; Department of Atmospheric Science, University of Wyoming, Laramie, WY, United States; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
Recommended Citation:
Yang X.,Wu K.,Wang H.,et al. Summertime ozone pollution in Sichuan Basin, China: Meteorological conditions, sources and process analysis[J]. Atmospheric Environment,2020-01-01,226