气候变化领域集成服务门户(CCPortal): Urban plume characteristics under various wind speed, heat flux, and stratification conditions

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DOI	10.1016/j.atmosenv.2020.117774
	Urban plume characteristics under various wind speed, heat flux, and stratification conditions
	Wang Q.; Hang J.; Fan Y.; Li Y.
发表日期	2020
ISSN	1352-2310
卷号	239
英文摘要	The adverse environmental impacts of the urban heat island (UHI) phenomenon have been known amid rapid urbanization in many parts of the world. UHI-induced circulation (UHIC) can affect pollutant dispersion and heat exchange. An UHIC can transform into an urban plume (or perturbed UHIC) in the presence of regional wind. To understand the urban plume characteristics, we apply the weather research and forecasting model to simulate UHIC in the presence of background wind. Particular attention is paid to settings with a buoyancy velocity ratio (R) of <2.0, where R is the ratio of the horizontal unperturbed UHIC velocity scale to background wind speed. Simulation results show that in weak stratification (N = 0.008 s−1), three types of perturbed UHIC flow patterns tend to occur upon changing background wind conditions: a strong UHIC, a distorted urban plume, or a strong urban plume. For R > 2.0, the strong UHIC flow pattern is characterized by upstream back-currents and returned leeside inflows. For 0.5 < R < 2.0, the distorted urban plume is characterized by the disappearance of upstream back-currents but occurrence of returned leeside inflows. For R < 0.5, the strong urban plume is characterized by the disappearance of both upstream back-currents and returned inflows. The advected length and inclined angle of perturbed UHIC show a linear relationship with R for R = 0.5–2.0, a nonlinear relationship for R > 3.0, and a transitional phase when R = 2.0–3.0. The stratification strength also influences the flow structures of urban plumes and pollutant dispersion. For example, stronger stratification with N = 0.014 s−1 prevents urban plumes from rising and contributes to the formation of returned leeside flow of urban plumes, resulting in a high tracer concentration over urban areas. © 2020 Elsevier Ltd
关键词	Advected length Flow regimes Idealized simulation Inclined angle Urban plume
语种	英语
scopus关键词	Flow patterns; Pollution; Weather forecasting; Wind; Adverse environmental impacts; Linear relationships; Non-linear relationships; Pollutant dispersions; Rapid urbanizations; Tracer concentration; Weak stratification; Weather research and forecasting models; Heat flux; buoyancy; flow pattern; forecasting method; heat flux; heat island; numerical model; plume; simulation; urbanization; wind velocity; air pollutant; Article; controlled study; forecasting; heat; meteorological phenomena; plume; priority journal; stratification; urban area; wind speed
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/248994
作者单位	Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China; School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, China; College of Civil Engineering and Architecture, Zhejiang University, Zhejiang, China
推荐引用方式 GB/T 7714	Wang Q.,Hang J.,Fan Y.,et al. Urban plume characteristics under various wind speed, heat flux, and stratification conditions[J],2020,239.
APA	Wang Q.,Hang J.,Fan Y.,&Li Y..(2020).Urban plume characteristics under various wind speed, heat flux, and stratification conditions.ATMOSPHERIC ENVIRONMENT,239.
MLA	Wang Q.,et al."Urban plume characteristics under various wind speed, heat flux, and stratification conditions".ATMOSPHERIC ENVIRONMENT 239(2020).