气候变化领域集成服务门户(CCPortal): Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight; not water solubility

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DOI	10.5194/acp-19-941-2019
	Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight; not water solubility
	Wang J.; Shilling J.E.; Liu J.; Zelenyuk A.; Bell D.M.; Petters M.D.; Thalman R.; Mei F.; Zaveri R.A.; Zheng G.
发表日期	2019
ISSN	16807316
起始页码	941
结束页码	954
卷号	19 期号:2
英文摘要	Aerosol particles strongly influence global climate by modifying the properties of clouds. An accurate assessment of the aerosol impact on climate requires knowledge of the concentration of cloud condensation nuclei (CCN), a subset of aerosol particles that can activate and form cloud droplets in the atmosphere. Atmospheric particles typically consist of a myriad of organic species, which frequently dominate the particle composition. As a result, CCN concentration is often a strong function of the hygroscopicity of organics in the particles. Earlier studies showed organic hygroscopicity increases nearly linearly with oxidation level. Such an increase in hygroscopicity is conventionally attributed to higher water solubility for more oxidized organics. By systematically varying the water content of activating droplets, we show that for the majority of secondary organic aerosols (SOAs), essentially all organics are dissolved at the point of droplet activation. Therefore, for droplet activation, the organic hygroscopicity is not limited by solubility but is dictated mainly by the molecular weight of organic species. Instead of increased water solubility as previously thought, the increase in the organic hygroscopicity with oxidation level is largely because (1) SOAs formed from smaller precursor molecules tend to be more oxidized and have lower average molecular weight and (2) during oxidation, fragmentation reactions reduce average organic molecule weight, leading to increased hygroscopicity. A simple model of organic hygroscopicity based on molecular weight, oxidation level, and volatility is developed, and it successfully reproduces the variation in SOA hygroscopicity with oxidation level observed in the laboratory and field studies. © Author(s) 2019.
语种	英语
scopus关键词	aerosol; cloud condensation nucleus; cloud droplet; hygroscopicity; molecular analysis; oxidation; solubility; water content
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/144699
作者单位	Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, United States; Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO, United States; Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, United States; Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, United States; Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University at Raleigh, Raleigh, NC 27695, United States; School of Environment, Harbin Institute of Technology, Harbin, 150001, China; Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen-PSI, 5232, Switzerland; Department of Chemistry, Snow College, Richfield, UT 84627, United States
推荐引用方式 GB/T 7714	Wang J.,Shilling J.E.,Liu J.,et al. Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight; not water solubility[J],2019,19(2).
APA	Wang J..,Shilling J.E..,Liu J..,Zelenyuk A..,Bell D.M..,...&Zheng G..(2019).Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight; not water solubility.Atmospheric Chemistry and Physics,19(2).
MLA	Wang J.,et al."Cloud droplet activation of secondary organic aerosol is mainly controlled by molecular weight; not water solubility".Atmospheric Chemistry and Physics 19.2(2019).