气候变化领域集成服务门户(CCPortal): Winter brown carbon over six of China's megacities: light absorption, molecularcharacterization, and improved source apportionment revealed by multilayerperceptron neural network

CCPortal

DOI	10.5194/acp-22-14893-2022
	Winter brown carbon over six of China's megacities: light absorption, molecularcharacterization, and improved source apportionment revealed by multilayerperceptron neural network
	Wang, Diwei; Shen, Zhenxing; Zhang, Qian; Lei, Yali; Zhang, Tian; Huang, Shasha; Sun, Jian; Xu, Hongmei; Cao, Junji
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	14893
结束页码	14904
卷号	22 期号:22 页码:12
英文摘要	Brown carbon (BrC) constitutes a large fraction of organic carbon and exhibits strong light absorption properties, thus affecting the global radiation budget. In this study, we investigated the light absorption properties, chemical functional bonds, and sources of BrC in six megacities in China, namely Beijing, Harbin, Xi'an, Chengdu, Guangzhou, and Wuhan. The average values of the BrC light absorption coefficient and the mass absorption efficiency at 365 nm in northern cities were higher than those in southern cities by 2.5 and 1.8 times, respectively, demonstrating the abundance of BrC present in northern China's megacities. Fourier transform infrared (FT-IR) spectra revealed sharp and intense peaks at 1640, 1458-1385, and 1090-1030 cm-1, which were ascribed to aromatic phenols, confirming the contribution of primary emission sources (e.g., biomass burning and coal combustion) to BrC. In addition, we noted peaks at 860, 1280-1260, and 1640 cm(-1), which were attributed to organonitrate and oxygenated phenolic groups, indicating that secondary BrC also existed in the six megacities. Positive matrix factorization (PMF) coupled with multilayer perceptron (MLP) neural network analysis was used to apportion the sources of BrC light absorption. The results showed that primary emissions (e.g., biomass burning, tailpipe emissions, and coal combustion) made a major contribution to BrC in the six megacities. However, secondary formation processes made a greater contribution to light absorption in the southern cities (17.9 %-21.2 %) than in the northern cities (2.1 %-10.2 %). These results can provide a basis for the more effective control of BrC to reduce its impacts on regional climates and human health.
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:000888026800001
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/273386
作者单位	Xi'an Jiaotong University; Xi'an University of Architecture & Technology; East China Normal University; Chinese Academy of Sciences; Institute of Earth Environment, CAS
推荐引用方式 GB/T 7714	Wang, Diwei,Shen, Zhenxing,Zhang, Qian,et al. Winter brown carbon over six of China's megacities: light absorption, molecularcharacterization, and improved source apportionment revealed by multilayerperceptron neural network[J],2022,22(22):12.
APA	Wang, Diwei.,Shen, Zhenxing.,Zhang, Qian.,Lei, Yali.,Zhang, Tian.,...&Cao, Junji.(2022).Winter brown carbon over six of China's megacities: light absorption, molecularcharacterization, and improved source apportionment revealed by multilayerperceptron neural network.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(22),12.
MLA	Wang, Diwei,et al."Winter brown carbon over six of China's megacities: light absorption, molecularcharacterization, and improved source apportionment revealed by multilayerperceptron neural network".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.22(2022):12.