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DOI	10.5194/acp-21-69-2021
	The enhancement of droplet collision by electric charges and atmospheric electric fields
	Guo S.; Xue H.
发表日期	2021
ISSN	1680-7316
起始页码	69
结束页码	85
卷号	21 期号:1
英文摘要	The effects of electric charges and fields on droplet collision-coalescence and the evolution of cloud droplet size distribution are studied numerically. Collision efficiencies for droplet pairs with radii from 2 to 1024 μm and charges from -32 r2 to +32 r2 (in units of elementary charge; droplet radius r in units of μm) in different strengths of downward electric fields (0, 200, and 400 V cm-1) are computed by solving the equations of motion for the droplets. It is seen that the collision efficiency is increased by electric charges and fields, especially for pairs of small droplets. These can be considered as being electrostatic effects. The evolution of the cloud droplet size distribution with the electrostatic effects is simulated using the stochastic collection equation. Results show that the electrostatic effect is not notable for clouds with the initial mean droplet radius of r = 15 μm or larger. For clouds with the initial r = 9 μm, the electric charge without a field could evidently accelerate raindrop formation compared to the uncharged condition, and the existence of electric fields further accelerates it. For clouds with the initial r = 6:5 μm, it is difficult for gravitational collision to occur, and the electric field could significantly enhance the collision process. The results of this study indicate that electrostatic effects can accelerate raindrop formation in natural conditions, particularly for polluted clouds. It is seen that the aerosol effect on the suppression of raindrop formation is significant in polluted clouds, when comparing the three cases with r = 15, 9, and 6.5 μm. However, the electrostatic effects can accelerate raindrop formation in polluted clouds and mitigate the aerosol effect to some extent. © 2021 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	aerosol; atmospheric electricity; cloud droplet; electric field; raindrop; size distribution; stochasticity
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/247245
作者单位	School of Physics, Peking University, Beijing, China
推荐引用方式 GB/T 7714	Guo S.,Xue H.. The enhancement of droplet collision by electric charges and atmospheric electric fields[J],2021,21(1).
APA	Guo S.,&Xue H..(2021).The enhancement of droplet collision by electric charges and atmospheric electric fields.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(1).
MLA	Guo S.,et al."The enhancement of droplet collision by electric charges and atmospheric electric fields".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.1(2021).