气候变化领域集成服务门户(CCPortal): A Generalized Mixing Length Closure for Eddy-Diffusivity Mass-Flux Schemes of Turbulence and Convection

CCPortal

DOI	10.1029/2020MS002161
	A Generalized Mixing Length Closure for Eddy-Diffusivity Mass-Flux Schemes of Turbulence and Convection
	Lopez-Gomez I.; Cohen Y.; He J.; Jaruga A.; Schneider T.
发表日期	2020
ISSN	19422466
卷号	12 期号:11
英文摘要	Because of their limited spatial resolution, numerical weather prediction and climate models have to rely on parameterizations to represent atmospheric turbulence and convection. Historically, largely independent approaches have been used to represent boundary layer turbulence and convection, neglecting important interactions at the subgrid scale. Here we build on an eddy-diffusivity mass-flux (EDMF) scheme that represents all subgrid-scale mixing in a unified manner, partitioning subgrid-scale fluctuations into contributions from local diffusive mixing and coherent advective structures and allowing them to interact within a single framework. The EDMF scheme requires closures for the interaction between the turbulent environment and the plumes and for local mixing. A second-order equation for turbulence kinetic energy (TKE) provides one ingredient for the diffusive local mixing closure, leaving a mixing length to be parameterized. Here, we propose a new mixing length formulation, based on constraints derived from the TKE balance. It expresses local mixing in terms of the same physical processes in all regimes of boundary layer flow. The formulation is tested at a range of resolutions and across a wide range of boundary layer regimes, including a stably stratified boundary layer, a stratocumulus-topped marine boundary layer, and dry convection. Comparison with large eddy simulations (LES) shows that the EDMF scheme with this diffusive mixing parameterization accurately captures the structure of the boundary layer and clouds in all cases considered. ©2020. The Authors.
英文关键词	boundary layer turbulence; eddy-diffusivity mass-flux scheme; subgrid-scale parameterization
语种	英语
scopus关键词	Atmospheric turbulence; Boundary layer flow; Boundary layers; Climate models; Kinetic energy; Kinetics; Large eddy simulation; Mixing; Parameterization; Predictive analytics; Weather forecasting; Boundary layer turbulence; Mixing-length formulations; Numerical weather prediction; Second-order equation; Stratified boundary layers; Stratocumulus-topped marine boundary layers; Turbulence kinetic energy; Turbulent environments; Atmospheric thermodynamics; atmospheric convection; atmospheric plume; boundary layer; climate prediction; eddy covariance; kinetic energy; marine atmosphere; stratiform cloud; stratocumulus; turbulence
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/156578
作者单位	Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
推荐引用方式 GB/T 7714	Lopez-Gomez I.,Cohen Y.,He J.,et al. A Generalized Mixing Length Closure for Eddy-Diffusivity Mass-Flux Schemes of Turbulence and Convection[J],2020,12(11).
APA	Lopez-Gomez I.,Cohen Y.,He J.,Jaruga A.,&Schneider T..(2020).A Generalized Mixing Length Closure for Eddy-Diffusivity Mass-Flux Schemes of Turbulence and Convection.Journal of Advances in Modeling Earth Systems,12(11).
MLA	Lopez-Gomez I.,et al."A Generalized Mixing Length Closure for Eddy-Diffusivity Mass-Flux Schemes of Turbulence and Convection".Journal of Advances in Modeling Earth Systems 12.11(2020).