气候变化领域集成服务门户(CCPortal): Momentum Transport in Shallow Cumulus Clouds and Its Parameterization by Higher-Order Closure

CCPortal

DOI	10.1029/2019MS001743
	Momentum Transport in Shallow Cumulus Clouds and Its Parameterization by Higher-Order Closure
	Larson V.E.; Domke S.; Griffin B.M.
发表日期	2019
ISSN	19422466
起始页码	3419
结束页码	3442
卷号	11 期号:11
英文摘要	It is challenging to parameterize subgrid vertical momentum fluxes in marine shallow cumulus layers that contain a jet in the profile of horizontal wind. In a large-eddy simulation of such a layer, it is found that the momentum flux in the direction of strongest wind magnitude has a three-layer structure. The lowest layer, from the ocean surface up to the jet maximum, has downgradient momentum flux. The middle layer, from the jet maximum up to an altitude several hundred meters above, has upgradient (i.e., countergradient) momentum flux because of transport of low-magnitude momentum upward through the jet maximum. In the upper layer, the layer-average momentum flux is weak. The budget of momentum flux shows that in the middle and upper layers, both the buoyancy production term and turbulent advection (i.e., third-order flux-of-flux) terms are important. To parameterize the profile of momentum flux in a single-column model, the momentum flux is prognosed in this study. The buoyancy production and flux-of-flux terms are parameterized by integrating them over a subgrid probability density function with an assumed normal-mixture shape. The resulting parameterized fluxes and mean-wind profiles are demonstrated to be comparable to those produced in large-eddy simulations, both for two marine shallow cumulus cases with upgradient fluxes and for a continental cumulus case and two stratocumulus cases with downgradient fluxes. In the two marine shallow cumulus cases, the parameterization is able to capture the upgradient momentum flux above the jet maximum and the weak momentum fluxes aloft. ©2019. The Authors.
英文关键词	higher-order closure; momentum flux; shallow cumulus clouds
语种	英语
scopus关键词	Budget control; Buoyancy; Clouds; Large eddy simulation; Parameterization; Probability density function; Down-gradient fluxes; Higher-order; Mean wind profiles; Momentum flux; Momentum transports; Shallow cumulus clouds; Single-column model; Three-layer structures; Momentum; advection; buoyancy; large eddy simulation; parameterization; probability density function; sea surface; stratocumulus
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156838
作者单位	Department of Mathematical Sciences, University of Wisconsin, Milwaukee, WI, United States; Pacific Northwest National Laboratory, Richland, WA, United States
推荐引用方式 GB/T 7714	Larson V.E.,Domke S.,Griffin B.M.. Momentum Transport in Shallow Cumulus Clouds and Its Parameterization by Higher-Order Closure[J],2019,11(11).
APA	Larson V.E.,Domke S.,&Griffin B.M..(2019).Momentum Transport in Shallow Cumulus Clouds and Its Parameterization by Higher-Order Closure.Journal of Advances in Modeling Earth Systems,11(11).
MLA	Larson V.E.,et al."Momentum Transport in Shallow Cumulus Clouds and Its Parameterization by Higher-Order Closure".Journal of Advances in Modeling Earth Systems 11.11(2019).