DOI: 10.1002/2014MS000376
Scopus记录号: 2-s2.0-85027953043
论文题名: Second-moment budgets in cloud topped boundary layers: A large-eddy simulation study
作者: Heinze R ; , Mironov D ; , Raasch S
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2015
卷: 7, 期: 2 起始页码: 510
结束页码: 536
语种: 英语
英文关键词: Advection
; Atmospheric boundary layer
; Atmospheric turbulence
; Boundary layers
; Buoyancy
; Kinetic energy
; Kinetics
; Large eddy simulation
; Models
; Reynolds equation
; Reynolds number
; Turbulent flow
; Cloud-topped boundary layer
; Dissipation rates
; Horizontal velocity
; Nocturnal marine stratocumulus
; parameterizations
; Second moments
; Second order moment
; Second-order closure
; Budget control
; atmospheric modeling
; boundary layer
; buoyancy
; cloud
; correlation
; covariance analysis
; cumulus
; ensemble forecasting
; flux measurement
; kinetic energy
; large eddy simulation
; parameterization
; pressure gradient
; Reynolds number
; strain
; trade wind
; turbulence
英文摘要: A detailed analysis of second-order moment budgets for cloud topped boundary layers (CTBLs) is performed using high-resolution large-eddy simulation (LES). Two CTBLs are simulated - one with trade wind shallow cumuli, and the other with nocturnal marine stratocumuli. Approximations to the ensemble-mean budgets of the Reynolds-stress components, of the fluxes of two quasi-conservative scalars, and of the scalar variances and covariance are computed by averaging the LES data over horizontal planes and over several hundred time steps. Importantly, the subgrid scale contributions to the budget terms are accounted for. Analysis of the LES-based second-moment budgets reveals, among other things, a paramount importance of the pressure scrambling terms in the Reynolds-stress and scalar-flux budgets. The pressure-strain correlation tends to evenly redistribute kinetic energy between the components, leading to the growth of horizontal-velocity variances at the expense of the vertical-velocity variance which is produced by buoyancy over most of both CTBLs. The pressure gradient-scalar covariances are the major sink terms in the budgets of scalar fluxes. The third-order transport proves to be of secondary importance in the scalar-flux budgets. However, it plays a key role in maintaining budgets of TKE and of the scalar variances and covariance. Results from the second-moment budget analysis suggest that the accuracy of description of the CTBL structure within the second-order closure framework strongly depends on the fidelity of parameterizations of the pressure scrambling terms in the flux budgets and of the third-order transport terms in the variance budgets. Key Points: Pressure-scrambling terms are crucial in Reynolds-stress and scalar-flux budgets Third-order transport plays key role in TKE and scalar (co)variance budgets TKE dissipation rate is underestimated with a diffusive advection scheme in LES © 2015. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/76050
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Institut für Meteorologie, KlimatologieLeibniz Universität Hannover, Hannover, Germany; Deutscher Wetterdienst, Offenbach, Germany
Recommended Citation:
Heinze R,, Mironov D,, Raasch S. Second-moment budgets in cloud topped boundary layers: A large-eddy simulation study[J]. Journal of Advances in Modeling Earth Systems,2015-01-01,7(2)