气候变化领域集成服务门户(CCPortal): Direct Quantification of Droplet Activation of Ambient Black Carbon Under Water Supersaturation

CCPortal

DOI	10.1029/2021JD034649
	Direct Quantification of Droplet Activation of Ambient Black Carbon Under Water Supersaturation
	Hu D.; Liu D.; Kong S.; Zhao D.; Wu Y.; Li S.; Ding S.; Zheng S.; Cheng Y.; Hu K.; Deng Z.; Wu Y.; Tian P.; Liu Q.; Huang M.; Ding D.
发表日期	2021
ISSN	2169897X
卷号	126 期号:13
英文摘要	Understanding the droplet activation of black carbon (BC) under water supersaturation (SS) conditions is crucial to estimate its lifetime (through activation scavenging) and indirect radiative impacts. However, directly probing the droplet activation of ambient BC is challenging because of the difficulty in discriminating the BC-containing particles (BCc) from other components. Here, we coupled the measurements of number concentrations between size-resolved cloud condensation nuclei (CCN) and individual BCc, achieving a direct quantification of droplet activation for ambient BCc. The activation diameters of BCc (D50_BCc), determined as the dry diameter at which 50% of BCc were activated, were 144 ± 21 nm under SS 0.2% corresponding to activated number fraction of total BCc of 60% ± 10%. D50_BCc was determined as a function of the coating hygroscopicity, and the organic content was observed as a limiting factor in controlling BCc activation. The activated BCc number concentration was predicted using the volume-weighted compositions within particle. The predicted CCN agreed well with the measurements for all particles, while overestimating the activated BCc number concentration by 71%, 27%, and 27% at SS = 0.1%, 0.2%, and 0.3%, respectively. The higher discrepancy under lower SS may result from the higher non-sphericity of BCc at large sizes. Therefore, only knowing the hygroscopicity distribution of bulk compositions may not be sufficient for estimating the activation of BCc, but considering additional factors such as the non-sphericity of BCc is necessary to estimate droplet activation. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	black carbon; cloud condensation nuclei; droplet activation; water supersaturation
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185118
作者单位	Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, China; Department of Earth and Environmental Sciences, University of Manchester, Manchester, United Kingdom; Department of Atmospheric Science, School of Environmental Sciences, China University of Geosciences, Wuhan, China; Beijing Weather Modification Office, Beijing, China; Key Laboratory for Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Hu D.,Liu D.,Kong S.,et al. Direct Quantification of Droplet Activation of Ambient Black Carbon Under Water Supersaturation[J],2021,126(13).
APA	Hu D..,Liu D..,Kong S..,Zhao D..,Wu Y..,...&Ding D..(2021).Direct Quantification of Droplet Activation of Ambient Black Carbon Under Water Supersaturation.Journal of Geophysical Research: Atmospheres,126(13).
MLA	Hu D.,et al."Direct Quantification of Droplet Activation of Ambient Black Carbon Under Water Supersaturation".Journal of Geophysical Research: Atmospheres 126.13(2021).