气候变化领域集成服务门户(CCPortal): On the drivers of droplet variability in alpine mixed-phase clouds

CCPortal

DOI	10.5194/acp-21-10993-2021
	On the drivers of droplet variability in alpine mixed-phase clouds
	Georgakaki P.; Bougiatioti A.; Wieder J.; Mignani C.; Ramelli F.; Kanji Z.A.; Henneberger J.; Hervo M.; Berne A.; Lohmann U.; Nenes A.; Nenes A.
发表日期	2021
ISSN	1680-7316
起始页码	10993
结束页码	11012
卷号	21 期号:14
英文摘要	Droplet formation provides a direct microphysical link between aerosols and clouds (liquid or mixed-phase), and its adequate description poses a major challenge for any atmospheric model. Observations are critical for evaluating and constraining the process. To this end, aerosol size distributions, cloud condensation nuclei (CCN), hygroscopicity, and lidar-derived vertical velocities were observed in alpine mixed-phase clouds during the Role of Aerosols and Clouds Enhanced by Topography on Snow (RACLETS) field campaign in the Davos, Switzerland, region during February and March 2019. Data from the mountain-top site of Weissfluhjoch (WFJ) and the valley site of Davos Wolfgang are studied. These observations are coupled with a state-of-the-art droplet activation parameterization to investigate the aerosol-cloud droplet link in mixed-phase clouds. The mean CCN-derived hygroscopicity parameter, κ, at WFJ ranges between 0.2-0.3, consistent with expectations for continental aerosols. κ tends to decrease with size, possibly from an enrichment in organic material associated with the vertical transport of fresh ultrafine particle emissions (likely from biomass burning) from the valley floor in Davos. The parameterization provides a droplet number that agrees with observations to within g1/4g25g%. We also find that the susceptibility of droplet formation to aerosol concentration and vertical velocity variations can be appropriately described as a function of the standard deviation of the distribution of updraft velocities, σw, as the droplet number never exceeds a characteristic limit, termed the "limiting droplet number", of g1/4g150-550gcm-3, which depends solely on σw. We also show that high aerosol levels in the valley, most likely from anthropogenic activities, increase the cloud droplet number, reduce cloud supersaturation (
语种	英语
scopus关键词	aerosol composition; atmospheric modeling; biomass burning; cloud condensation nucleus; cloud microphysics; concentration (composition); droplet; Davos; Graubunden; Switzerland
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/246721
作者单位	Laboratory of Atmospheric Processes and Their Impacts, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland; Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, 15236, Greece; Department of Environmental Systems Science, Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, 8092, Switzerland; Department of Environmental Sciences, University of Basel, Basel, 4056, Switzerland; Federal Office of Meteorology and Climatology, MeteoSwiss, Payerne, 1530, Switzerland; Environmental Remote Sensing Laboratory, School of Architecture,Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland; Center for Studies of Air Quality and Climate Change, Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, 26504, Greece
推荐引用方式 GB/T 7714	Georgakaki P.,Bougiatioti A.,Wieder J.,et al. On the drivers of droplet variability in alpine mixed-phase clouds[J],2021,21(14).
APA	Georgakaki P..,Bougiatioti A..,Wieder J..,Mignani C..,Ramelli F..,...&Nenes A..(2021).On the drivers of droplet variability in alpine mixed-phase clouds.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(14).
MLA	Georgakaki P.,et al."On the drivers of droplet variability in alpine mixed-phase clouds".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.14(2021).