气候变化领域集成服务门户(CCPortal): Formation mechanism of a severe air pollution event: A case study in the Sichuan Basin; Southwest China

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DOI	10.1016/j.atmosenv.2020.118135
	Formation mechanism of a severe air pollution event: A case study in the Sichuan Basin; Southwest China
	Hu Y.; Wang S.
发表日期	2021
ISSN	1352-2310
卷号	246
英文摘要	The formation mechanism of air pollution events in the Sichuan Basin (SB), which is the fourth most heavily polluted area in China, has not been fully revealed. This study investigated the formation mechanism of a severe air pollution event over the SB using synoptic approaches and model simulations. The results can be summarized as follows: (1) Heavy air pollution in the SB was characterized by low visibility, low atmospheric boundary layer (ABL) height, high temperature, high relative humidity, strong temperature inversion layer, subsidence in the troposphere, high water vapor content between 500 and 900 hPa, southerly winds in the low troposphere, and surface winds with low speed and irregular direction. (2) Air quality in the SB was closely related to the weather system at 700 hPa over the basin. When the 700 hPa weather system affecting the SB was a high-pressure system, the subsidence and stable atmospheric stratification increased the air pollutant concentrations near the ground. When the 700 hPa weather system affecting the SB was a low-pressure system and the basin was in front of this low-pressure system, southwesterly warm and moist airflow and adiabatic subsidence warming formed the thick temperature inversion layer over the basin. As a result, the temperature inversion layer trapped air pollutants in the basin and induced the heavy air pollution event. When the 700 hPa weather system over the SB was a low-pressure system and the basin was behind the low-pressure system, the dry and cold airflow from the north invaded southward to the basin and broke the temperature inversion layer. Consequently, air pollutants dispersed vertically, resulting in decreased concentrations near the ground. (3) Air pollutants from December 17, 2017 to January 4, 2018 were mainly from local emissions. (4) The WRF-Chem model not only reproduced the variations in PM2.5 concentrations, the ABL height, and the height-time cross-sections of temperature, water vapor content, and wind over Chengdu during the air pollution event, but also revealed the formation mechanism of this heavy air pollution event. The results of this study reveal the formation mechanism of winter heavy air pollution events over the SB and help develop effective regional air quality management strategies to reduce the likelihood of local air pollution events and minimize the adverse impacts of air pollution. © 2020 Elsevier Ltd
英文关键词	Air quality; Atmospheric boundary layer; Atmospheric humidity; Climatology; Inversion layers; Quality management; Subsidence; Troposphere; Water pollution; Water vapor; Air pollutant concentrations; Atmospheric stratification; High pressure system; High relative humidities; Local air pollutions; Low pressure systems; Temperature inversion layers; Water vapor contents; Atmospheric temperature; air quality; airflow; atmospheric pollution; boundary layer; inversion layer; pollutant transport; stratification; subsidence; temperature inversion; water vapor; wind velocity; adiabaticity; air quality; airflow; article; boundary layer; China; cold stress; high temperature; humidity; hypobarism; meteorology; particulate matter 2.5; simulation; troposphere; velocity; visibility; warming; water vapor; weather; winter; Chengdu; China; Sichuan; Sichuan Basin
语种	英语
来源期刊	Atmospheric Environment
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169062
作者单位	State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, College of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu, 610225, China; Key Laboratory of Arid Climate Change and Reducing Disaster in Gansu Province, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, China; Zunyi Academician Center, Chinese Academy of Sciences & Chinese Academy of Engineering, Zunyi, Guizhou Province 563000, China
推荐引用方式 GB/T 7714	Hu Y.,Wang S.. Formation mechanism of a severe air pollution event: A case study in the Sichuan Basin; Southwest China[J]. 中国科学院西北生态环境资源研究院,2021,246.
APA	Hu Y.,&Wang S..(2021).Formation mechanism of a severe air pollution event: A case study in the Sichuan Basin; Southwest China.Atmospheric Environment,246.
MLA	Hu Y.,et al."Formation mechanism of a severe air pollution event: A case study in the Sichuan Basin; Southwest China".Atmospheric Environment 246(2021).