Vertical profile of particle hygroscopicity and CCN effectiveness during winter in Beijing: insight into the hygroscopicity transition threshold of black carbon

doi:10.1039/d0fd00094a

IEECAS OpenIR > 粉尘与环境研究室

	Vertical profile of particle hygroscopicity and CCN effectiveness during winter in Beijing: insight into the hygroscopicity transition threshold of black carbon
	Watson, John G.1,2,3; Cao, Junji 2,4; Wang, Xiaoliang 1,3; Chow, Judith C.1,2,3
通讯作者	Watson, John G.() ; Cao, Junji(cao@loess.llqg.ae.cn)
	2021-03-01
发表期刊	FARADAY DISCUSSIONS
ISSN	1359-6640
卷号	226 期号:0 页码:255-289
摘要	The hygroscopicity and ability of aerosol particles to act as cloud condensation nuclei (CCN) is important in determining their lifetime and role in aerosol-cloud interactions, thereby influencing cloud formation and climate. Previous studies have used the aerosol hygroscopic properties measured at the ground to evaluate the influence on cloud formation in the atmosphere, which may introduce uncertainty associated with aerosol hygroscopicity variability with altitude. In this study, the CCN behaviour and hygroscopic properties of daily filter collections of PM2.5 from three different heights (8, 120, 260 m) on a tower in Beijing were determined in the laboratory using water, water/methanol and methanol as the atomization solvents. Whilst there was substantial temporal variability in particle concentration and composition, there was little obvious difference in aerosol CCN and hygroscopic behaviour at different heights, although the planetary boundary layer height (PBLH) reduced to below the tower height during the nighttime, suggesting that use of surface hygroscopicity measurements is sufficient for the estimation of aerosol particle activation in clouds. Additionally, the critical coating thickness (in terms of mass ratio of coating/refractory BC, MRc) defining the BC transition between being hydrophobic to hydrophilic, was determined by combining hygroscopic tandem differential mobility analyser (H-TDMA), centrifugal particle mass analyzer (CPMA) and single particle soot photometer (SP2) measurements. The MRc of 250 nm BC-containing particles increased from a background value of between 0.8 and 1.6 to around 4.6 at the onset of the growth event of nanoparticles, decreasing monotonically back to the background level as the event progressed. This indicates that large particles do not act as an effective pre-existing condensation sink of the hygroscopic vapours during the nanoparticle growth events, leading to the 250 nm BC particles requiring more coating materials to transition between being hydrophobic and hydrophilic. These findings show that large particles may be less important in suppressing the new particle formation and subsequent growth in the atmosphere.
DOI	10.1039/d0fd00094a
收录类别	SCI ; SCI
语种	英语
资助项目	Sino-Swiss Cooperation on Air Pollution Source Apportionment for Better Air at the State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China[7F-09802.01]
WOS研究方向	Chemistry
项目资助者	Sino-Swiss Cooperation on Air Pollution Source Apportionment for Better Air at the State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
WOS类目	Chemistry, Physical
WOS记录号	WOS:000631999100013
出版者	ROYAL SOC CHEMISTRY
引用统计
文献类型	期刊论文
条目标识符	http://ir.ieecas.cn/handle/361006/16250
专题	粉尘与环境研究室
通讯作者	Watson, John G.; Cao, Junji
作者单位	1.Desert Res Inst, Div Atmospher Sci, Reno, NV 89506 USA 2.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian, Peoples R China 3.Univ Nevada, Grad Fac, Reno, NV 89557 USA 4.Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Watson, John G.,Cao, Junji,Wang, Xiaoliang,et al. Vertical profile of particle hygroscopicity and CCN effectiveness during winter in Beijing: insight into the hygroscopicity transition threshold of black carbon[J]. FARADAY DISCUSSIONS,2021,226(0):255-289.
APA	Watson, John G.,Cao, Junji,Wang, Xiaoliang,&Chow, Judith C..(2021).Vertical profile of particle hygroscopicity and CCN effectiveness during winter in Beijing: insight into the hygroscopicity transition threshold of black carbon.FARADAY DISCUSSIONS,226(0),255-289.
MLA	Watson, John G.,et al."Vertical profile of particle hygroscopicity and CCN effectiveness during winter in Beijing: insight into the hygroscopicity transition threshold of black carbon".FARADAY DISCUSSIONS 226.0(2021):255-289.