气候变化领域集成服务门户(CCPortal): Drivers of cloud droplet number variability in the summertime in the southeastern United States

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DOI	10.5194/acp-20-12163-2020
	Drivers of cloud droplet number variability in the summertime in the southeastern United States
	Bougiatioti A.; Nenes A.; Lin J.J.; Brock C.A.; De Gouw J.A.; Liao J.; Middlebrook A.M.; Welti A.
发表日期	2020
ISSN	16807316
起始页码	12163
结束页码	12176
卷号	20 期号:20
英文摘要	Here we analyze regional-scale data collected on board the NOAA WP-3D aircraft during the 2013 Southeast Nexus (SENEX) campaign to study the aerosol cloud droplet link and quantify the sensitivity of droplet number to aerosol number, chemical composition, and vertical velocity. For this, the observed aerosol size distributions, chemical composition, and vertical-velocity distribution are introduced into a state-of-the-art cloud droplet parameterization to show that cloud maximum supersaturations in the region range from 0.02 % to 0.52 %, with an average of 0:14 ± 0:05 %. Based on these low values of supersaturation, the majority of activated droplets correspond to particles with a dry diameter of 90 nm and above. An important finding is that the standard deviation of the vertical velocity (sw) exhibits considerable diurnal variability (ranging from 0.16 ms-1 during nighttime to over 1.2 ms-1 during day), and it tends to covary with total aerosol number (Na). This sw Na covariance amplifies the predicted response in cloud droplet number (Nd) to Na increases by 3 to 5 times compared to expectations based on Na changes alone. This amplified response is important given that droplet formation is often velocity-limited and therefore should normally be insensitive to aerosol changes. We also find that Nd cannot exceed a characteristic concentration that depends solely on sw. Correct consideration of sw and its covariance with time and Na is important for fully understanding aerosol cloud interactions and the magnitude of the aerosol indirect effect. Given that model assessments of aerosol cloud climate interactions do not routinely evaluate for overall turbulence or its covariance with other parameters, datasets and analyses such as the one presented here are of the highest priority to address unresolved sources of hydrometeor variability, bias, and the response of droplet number to aerosol perturbations. © 2020 Author(s).
语种	英语
scopus关键词	aerosol; chemical composition; cloud droplet; diurnal variation; NOAA satellite; parameterization; size distribution; summer; supersaturation; United States
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/143879
作者单位	Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, 15236, Greece; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Laboratory of Atmospheric Processes and Their Impacts, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland; Institute for Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, 26504, Greece; Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305, United States; Cooperative Institute for Research in Environmental Sciences, Univ. of Colorado, Boulder, CO 80309, United States; Nano and Molecular Systems Research Unit, University of Oulu, Oulu, 90014, Finland; Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO 80309, United States; Atmospheric Chemistry and Dynamic Laboratory, NASA Goddard S...
推荐引用方式 GB/T 7714	Bougiatioti A.,Nenes A.,Lin J.J.,et al. Drivers of cloud droplet number variability in the summertime in the southeastern United States[J],2020,20(20).
APA	Bougiatioti A..,Nenes A..,Lin J.J..,Brock C.A..,De Gouw J.A..,...&Welti A..(2020).Drivers of cloud droplet number variability in the summertime in the southeastern United States.Atmospheric Chemistry and Physics,20(20).
MLA	Bougiatioti A.,et al."Drivers of cloud droplet number variability in the summertime in the southeastern United States".Atmospheric Chemistry and Physics 20.20(2020).