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DOI	10.5194/acp-20-6291-2020
	Ensemble daily simulations for elucidating cloud-aerosol interactions under a large spread of realistic environmental conditions
	Dagan G.; Stier P.
发表日期	2020
ISSN	1680-7316
起始页码	6291
结束页码	6303
卷号	20 期号:11
英文摘要	Aerosol effects on cloud properties and the atmospheric energy and radiation budgets are studied through ensemble simulations over two month-long periods during the NARVAL campaigns (Next-generation Aircraft Remote-Sensing for Validation Studies, December 2013 and August 2016). For each day, two simulations are conducted with low and high cloud droplet number concentrations (CDNCs), representing low and high aerosol concentrations, respectively. This large data set, which is based on a large spread of co-varying realistic initial conditions, enables robust identification of the effect of CDNC changes on cloud properties. We show that increases in CDNC drive a reduction in the top-of-atmosphere (TOA) net shortwave flux (more reflection) and a decrease in the lower-tropospheric stability for all cases examined, while the TOA longwave flux and the liquid and ice water path changes are generally positive. However, changes in cloud fraction or precipitation, that could appear significant for a given day, are not as robustly affected, and, at least for the summer month, are not statistically distinguishable from zero. These results highlight the need for using a large sample of initial conditions for cloud-aerosol studies for identifying the significance of the response. In addition, we demonstrate the dependence of the aerosol effects on the season, as it is shown that the TOA net radiative effect is doubled during the winter month as compared to the summer month. By separating the simulations into different dominant cloud regimes, we show that the difference between the different months emerges due to the compensation of the longwave effect induced by an increase in ice content as compared to the shortwave effect of the liquid clouds. The CDNC effect on the longwave flux is stronger in the summer as the clouds are deeper and the atmosphere is more unstable. © 2020 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	aerosol composition; aerosol formation; concentration (composition); ensemble forecasting; radiative transfer; troposphere
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/141312
作者单位	Department of Physics Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom
推荐引用方式 GB/T 7714	Dagan G.,Stier P.. Ensemble daily simulations for elucidating cloud-aerosol interactions under a large spread of realistic environmental conditions[J],2020,20(11).
APA	Dagan G.,&Stier P..(2020).Ensemble daily simulations for elucidating cloud-aerosol interactions under a large spread of realistic environmental conditions.Atmospheric Chemistry and Physics,20(11).
MLA	Dagan G.,et al."Ensemble daily simulations for elucidating cloud-aerosol interactions under a large spread of realistic environmental conditions".Atmospheric Chemistry and Physics 20.11(2020).