气候变化领域集成服务门户(CCPortal): Variability in the mass absorption cross section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz; Germany) in winter

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DOI	10.5194/acp-21-635-2021
	Variability in the mass absorption cross section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz; Germany) in winter
	Yuan J.; Lewis Modini R.; Zanatta M.; Herber A.B.; Müller T.; Wehner B.; Poulain L.; Tuch T.; Baltensperger U.; Gysel-Beer M.
发表日期	2021
ISSN	1680-7316
起始页码	635
结束页码	655
卷号	21 期号:2
英文摘要	Properties of atmospheric black carbon (BC) particles were characterized during a field experiment at a rural background site (Melpitz, Germany) in February 2017. BC absorption at a wavelength of 870 nm was measured by a photoacoustic extinctiometer, and BC physical properties (BC mass concentration, core size distribution and coating thickness) were measured by a single-particle soot photometer (SP2). Additionally, a catalytic stripper was used to intermittently remove BC coatings by alternating between ambient and thermo-denuded conditions. From these data the mass absorption cross section of BC (MACBC) and its enhancement factor (EMAC) were inferred for essentially waterfree aerosol as present after drying to low relative humidity (RH). Two methods were applied independently to investigate the coating effect on EMAC: A correlation method (MACBC; ambient vs. BC coating thickness) and a denuding method (MACBC; ambient vs. MACBC; denuded). Observed EMAC values varied from 1.0 to 1.6 (lower limit from denuding method) or 1:2 to 1.9 (higher limit from correlation method), with the mean coating volume fraction ranging from 54% to 78% in the dominating mass equivalent BC core diameter range of 200?220 nm.MACBC and EMAC were strongly correlated with coating thickness of BC. By contrast, other potential drivers of EMAC variability, such as different BC sources (air mass origin and absorption Angström exponent), coating composition (ratio of inorganics to organics) and BC core size distribution, had only minor effects. These results for ambient BC measured at Melpitz during winter show that the lensing effect caused by coatings on BC is the main driver of the variations in MACBC and EMAC, while changes in other BC particle properties such as source, BC core size or coating composition play only minor roles at this rural background site with a large fraction of aged particles. Indirect evidence suggests that potential dampening of the lensing effect due to unfavorable morphology was most likely small or even negligible. © 2021 Mary Ann Liebert Inc.. All rights reserved.
英文关键词	absorption; aerosol; black carbon; concentration (composition); relative humidity; seasonal variation; Germany; Melpitz; Saxony
语种	英语
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/168833
作者单位	Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, 5232, Switzerland; Helmholtz Center for Polar and Marine Research, Alfred-Wegener-Institute, Am Handelshafen 12, Bremerhaven, 27570, Germany; Experimental Aerosol and Cloud Microphysics Department, Leibniz Institute for Tropospheric Research, Permoserstraße 15, Leipzig, 04318, Germany
推荐引用方式 GB/T 7714	Yuan J.,Lewis Modini R.,Zanatta M.,et al. Variability in the mass absorption cross section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz; Germany) in winter[J],2021,21(2).
APA	Yuan J..,Lewis Modini R..,Zanatta M..,Herber A.B..,Müller T..,...&Gysel-Beer M..(2021).Variability in the mass absorption cross section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz; Germany) in winter.Atmospheric Chemistry and Physics,21(2).
MLA	Yuan J.,et al."Variability in the mass absorption cross section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz; Germany) in winter".Atmospheric Chemistry and Physics 21.2(2021).