气候变化领域集成服务门户(CCPortal): Vertical Variation of Turbulent Entrainment Mixing Processes in Marine Stratocumulus Clouds Using High-Resolution Digital Holography

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DOI	10.1029/2020JD033527
	Vertical Variation of Turbulent Entrainment Mixing Processes in Marine Stratocumulus Clouds Using High-Resolution Digital Holography
	Desai N.; Liu Y.; Glienke S.; Shaw R.A.; Lu C.; Wang J.; Gao S.
发表日期	2021
ISSN	2169897X
卷号	126 期号:7
英文摘要	Marine stratocumulus clouds contribute significantly to the Earth's radiation budget due to their extensive coverage and high albedo. Yet, subgrid variability in cloud properties, such as aerosol concentration, droplet number, and precipitation rates, lead to considerable errors in global climate models. While these clouds usually have small vertical extent, turbulent entrainment-mixing and precipitation can generate significant variations in droplet number, size, and relative dispersion with altitude. Here, we analyze turbulent entrainment-mixing processes and the variability in cloud microphysical properties as a function of height within a warm marine stratocumulus cloud layer over the Eastern North Atlantic. We use high-resolution airborne holographic measurements and compare them with local turbulence measurements. We find that entrainment-mixing is primarily inhomogeneous near cloud top and homogeneous near cloud base. Further analysis of Damköhler number and transition scale number are able to explain the mixing mechanisms at different cloud heights using phase relaxation but not droplet evaporation as the microphysical time scale. A modified droplet evaporation time scale that considers local saturation deficit using a simple linear mixing model is developed, and it is able to reliably explain the observed mixing mechanisms. This study reinforces the importance of turbulent mixing and the use of appropriate microphysical time scales in determining cloud microphysical processes. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Boundary layer; clouds; entrainment; holography; microphysics; turbulence
语种	英语
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/185341
作者单位	Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, United States; Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States; Atmospheric Sciences Program, Department of Physics, Michigan Technological University, Houghton, MI, United States; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol Cloud Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing, China; Department of Energy, Environmental and Chemical Engineering, Center for Aerosol Science and Engineering, University of Washington, St. Louis, MO, United States
推荐引用方式 GB/T 7714	Desai N.,Liu Y.,Glienke S.,et al. Vertical Variation of Turbulent Entrainment Mixing Processes in Marine Stratocumulus Clouds Using High-Resolution Digital Holography[J],2021,126(7).
APA	Desai N..,Liu Y..,Glienke S..,Shaw R.A..,Lu C..,...&Gao S..(2021).Vertical Variation of Turbulent Entrainment Mixing Processes in Marine Stratocumulus Clouds Using High-Resolution Digital Holography.Journal of Geophysical Research: Atmospheres,126(7).
MLA	Desai N.,et al."Vertical Variation of Turbulent Entrainment Mixing Processes in Marine Stratocumulus Clouds Using High-Resolution Digital Holography".Journal of Geophysical Research: Atmospheres 126.7(2021).