气候变化领域集成服务门户(CCPortal): Factors Affecting Entrainment Rate in Deep Convective Clouds and Parameterizations

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DOI	10.1029/2021JD034881
	Factors Affecting Entrainment Rate in Deep Convective Clouds and Parameterizations
	Xu X.; Sun C.; Lu C.; Liu Y.; Zhang G.J.; Chen Q.
发表日期	2021
ISSN	2169-897X
卷号	126 期号:15
英文摘要	The parameterization of cloud entrainment rate has been problematic for many years, hindering the accurate representation of convective processes in large-scale models. Here, we extend our previous work on individual shallow convection to ensemble deep convection. Entrainment rate is estimated based on three-dimensional convective clouds from August 19 to 20, 1999, during the Kwajalein Experiment, simulated using a high-resolution cloud-resolving model. They are found to be negatively correlated with both vertical velocity and buoyancy, and positively correlated with the vertical divergence of the vertical velocity and with the reciprocal of cloud radii. The physical mechanisms underlying these relationships are interpreted. It is found that the parameterizations with multiple properties perform better than those with a single property. Entrainment rate and relative humidity of entrained air are positively correlated at temperature higher than 0°C, but negatively correlated at temperature lower than 0°C. Relative humidity is also included in the parameterization of entrainment rate, which differs from our previous work on shallow cumulus clouds and other studies. Finally, two forms of parameterization for entrainment rate are recommended. The first treats the entrainment rate as a function of the vertical velocity and buoyancy for temperature higher than 0°C, but as a function of relative humidity and buoyancy for temperature lower than 0°C. The second involves an equation that relates entrainment rate to vertical velocity and buoyancy regardless of temperature. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	convective clouds; entrainment rate; model parameterization
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/237088
作者单位	Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China; Taizhou Environmental Monitoring Center, Taizhou, China; Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, United States; Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States
推荐引用方式 GB/T 7714	Xu X.,Sun C.,Lu C.,et al. Factors Affecting Entrainment Rate in Deep Convective Clouds and Parameterizations[J],2021,126(15).
APA	Xu X.,Sun C.,Lu C.,Liu Y.,Zhang G.J.,&Chen Q..(2021).Factors Affecting Entrainment Rate in Deep Convective Clouds and Parameterizations.Journal of Geophysical Research: Atmospheres,126(15).
MLA	Xu X.,et al."Factors Affecting Entrainment Rate in Deep Convective Clouds and Parameterizations".Journal of Geophysical Research: Atmospheres 126.15(2021).