气候变化领域集成服务门户(CCPortal): Impact of urban heat island on inorganic aerosol in the lower free tropospnere: a case study in Hangznou, China

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DOI	10.5194/acp-22-10623-2022
	Impact of urban heat island on inorganic aerosol in the lower free tropospnere: a case study in Hangznou, China
	Kang, Hanqing; Zhu, Bin; de Leeuw, Gerrit; Yu, Bu; van der, Ronald J. A.; Lu, Wen
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	10623
结束页码	10634
卷号	22 期号:16 页码:12
英文摘要	Urban heat island (UHI) and urban air pollution are two major environmental problems faced by many metropolises. The UHI affects air pollution by changing the local circulation and the chemical reaction environment, e.g. air temperature and relative humidity. In this study, the WRF-CMAQ (Weather Research and Forecasting Community Multiscale Air Quality) model was used to investigate the impact of an UHI on the vertical distribution of aerosol particles, especially secondary inorganic aerosol (SIA), taking the strong UHI in Hangzhou, China, as an example. The results show that during the day with the strongest UHI case of the 8 d simulation, the UHI effect resulted in a decrease in the PM2.5 concentrations in the boundary layer (BL) by about 33 %, accompanied by an increase in the lower free troposphere (LFT) by about 19 %. This is mostly attributed to the UHI circulation (UHIC) effect, which accounted for 91 % of the UHI-induced variations in PM2.5, rather than the UHI temperature or humidity effects, which contributed only 5 % and 4 %, respectively. The UHIC effect plays a dominant role, ranging from 72 % to 93 %, in UHI-induced PM2.5 variation in all eight UHI cases. The UHIC not only directly transports aerosol particles from ground level to the LFT but also redistributes aerosol precursors. During the strongest UHI case, about 80 % of the UHIC-induced increase in the aerosol particles in the LFT is due to direct transport of aerosol particles, whereas the other 20 % is due to secondary aerosol formation resulting from the transport of aerosol precursor gases. Of this 20 %, 91 % is contributed by SIA, especially ammonium nitrate aerosol formed from ammonia and nitric acid. In the atmosphere, ammonium nitrate is in equilibrium with ammonia and nitric acid, and the equilibrium depends on the ambient temperature. In the lower urban BL, the temperature is higher than in the LFT, and the ammonium nitrate equilibrium in the lower BL is more toward the gas phase than in the LFT; when these gases are transported by the UHIC into the colder LFT, the equilibrium shifts to the aerosol phase. Hence, the UHIC changes the vertical distribution of SIA, which may have potential implications on the radiation budget, cloud formation, and precipitation in the urban and surrounding areas.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000843384400001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273818
作者单位	China Meteorological Administration; Nanjing University of Information Science & Technology; Nanjing University of Information Science & Technology; Royal Netherlands Meteorological Institute
推荐引用方式 GB/T 7714	Kang, Hanqing,Zhu, Bin,de Leeuw, Gerrit,et al. Impact of urban heat island on inorganic aerosol in the lower free tropospnere: a case study in Hangznou, China[J],2022,22(16):12.
APA	Kang, Hanqing,Zhu, Bin,de Leeuw, Gerrit,Yu, Bu,van der, Ronald J. A.,&Lu, Wen.(2022).Impact of urban heat island on inorganic aerosol in the lower free tropospnere: a case study in Hangznou, China.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(16),12.
MLA	Kang, Hanqing,et al."Impact of urban heat island on inorganic aerosol in the lower free tropospnere: a case study in Hangznou, China".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.16(2022):12.