气候变化领域集成服务门户(CCPortal): Mesoscale structure of the atmospheric boundary layer and its impact on regional air pollution: A case study

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DOI	10.1016/j.atmosenv.2021.118511
	Mesoscale structure of the atmospheric boundary layer and its impact on regional air pollution: A case study
	Jin X.; Cai X.; Yu M.; Wang X.; Song Y.; Kang L.; Zhang H.; Zhu T.
发表日期	2021
ISSN	1352-2310
卷号	258
英文摘要	The atmospheric boundary layer (ABL) is known for its vertical structure in affecting air pollution due to the dilution and ventilation capacity. But how this effect playing over horizontal scales is not well investigated. This study reveals the ABL structure over a sub-synoptic scale or mesoscale related to regional PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm) pollution in the North China Plain (NCP). A typical PM2.5 pollution episode from December 1–4, 2017, is chosen for analysis, which is characterized by the rapid development of a vast polluted air mass along the mountainous side of the NCP extended hundreds of kilometers. In association with this episode, a shallow trough and a warm tongue at 850 hPa, with warm air advection in the upper layer and an orographic trough at the surface, provide favorable conditions for low-level warm front formation in the NCP. Surface meteorological data from 116 observatories and pollution-monitoring data recorded at 40 stations on the NCP are used to diagnose the hourly evolution of the meteorological and PM2.5 concentration fields, based on the California Meteorological (CALMET) model and a simple interpolation scheme. In addition to the surface wind, the equivalent potential temperature (EPT) is used to analyze air-mass boundaries or fronts at the surface. The results show that a block of colder air mass is gradually confined by warmer air, driven both from the southeast by a warm front and from the northwest by the thermal effect of the mountains. Consequently, a polluted air mass develops, with sharp boundaries indicated by both the discontinuity of wind fields and a strong gradient in the EPT. Numerical simulation using the Weather Research and Forecast model reproduces the meteorological evolution at the surface, revealing a three-dimensional ABL structure during this episode. With a dome-like warm cap covering the colder polluted air mass, an abrupt drop of ABL height occurs at the cross section from outside into this zone. Strong stratification suppresses the daytime ABL height to as low as 300 m over this zone. Thus, the cold air mass is confined not only laterally but also vertically. This ABL structure persisted throughout the daytime and night, in addition to weak winds in the nearly isolated air mass, which constitutes adverse dispersion conditions. This may help to explain the simultaneous increase in PM2.5 concentrations over a vast area of the NCP. © 2021 Elsevier Ltd
关键词	Air mass Atmospheric boundary layer Front North China Plain Regional air pollution
语种	英语
scopus关键词	Air pollution; Atmospheric movements; Computational fluid dynamics; Horizontal wells; Meteorology; Weather forecasting; Air mass; Boundary layer structure; Front; North China Plain; PM$-2.5$; Polluted air mass; Potential temperature; Regional air pollution; Warm air; Warm fronts; Atmospheric boundary layer; advection; air mass; atmospheric pollution; boundary layer; mesoscale meteorology; orographic effect; pollution monitoring; advection; article; boundary layer; California; China; cold air; computer simulation; night; particulate matter 2.5; pollution monitoring; tongue; weather; California; China; North China Plain; United States
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248379
作者单位	College of Environmental Sciences and Engineering, State Key Lab of Environmental Simulation and Pollution Control, Peking University, Beijing, 100871, China; Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, 100871, China
推荐引用方式 GB/T 7714	Jin X.,Cai X.,Yu M.,et al. Mesoscale structure of the atmospheric boundary layer and its impact on regional air pollution: A case study[J],2021,258.
APA	Jin X..,Cai X..,Yu M..,Wang X..,Song Y..,...&Zhu T..(2021).Mesoscale structure of the atmospheric boundary layer and its impact on regional air pollution: A case study.ATMOSPHERIC ENVIRONMENT,258.
MLA	Jin X.,et al."Mesoscale structure of the atmospheric boundary layer and its impact on regional air pollution: A case study".ATMOSPHERIC ENVIRONMENT 258(2021).