DOI: 10.1002/2016MS000778
Scopus记录号: 2-s2.0-85026642909
论文题名: Numerics and subgrid-scale modeling in large eddy simulations of stratocumulus clouds
作者: Pressel K ; G ; , Mishra S ; , Schneider T ; , Kaul C ; M ; , Tan Z
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2017
卷: 9, 期: 2 起始页码: 1342
结束页码: 1365
语种: 英语
英文关键词: Boundary layers
; Clouds
; Equations of motion
; Boundary layer clouds
; Essentially non-oscillatory
; Initial and boundary conditions
; Numerical dissipation
; numerics
; stratocumulus
; Sub-grid scale models
; WENO
; Large eddy simulation
; boundary condition
; boundary layer
; climate effect
; entrainment
; large eddy simulation
; numerical model
; stratocumulus
英文摘要: Stratocumulus clouds are the most common type of boundary layer cloud; their radiative effects strongly modulate climate. Large eddy simulations (LES) of stratocumulus clouds often struggle to maintain fidelity to observations because of the sharp gradients occurring at the entrainment interfacial layer at the cloud top. The challenge posed to LES by stratocumulus clouds is evident in the wide range of solutions found in the LES intercomparison based on the DYCOMS-II field campaign, where simulated liquid water paths for identical initial and boundary conditions varied by a factor of nearly 12. Here we revisit the DYCOMS-II RF01 case and show that the wide range of previous LES results can be realized in a single LES code by varying only the numerical treatment of the equations of motion and the nature of subgrid-scale (SGS) closures. The simulations that maintain the greatest fidelity to DYCOMS-II observations are identified. The results show that using weighted essentially non-oscillatory (WENO) numerics for all resolved advective terms and no explicit SGS closure consistently produces the highest-fidelity simulations. This suggests that the numerical dissipation inherent in WENO schemes functions as a high-quality, implicit SGS closure for this stratocumulus case. Conversely, using oscillatory centered difference numerical schemes for momentum advection, WENO numerics for scalars, and explicitly modeled SGS fluxes consistently produces the lowest-fidelity simulations. We attribute this to the production of anomalously large SGS fluxes near the cloud tops through the interaction of numerical error in the momentum field with the scalar SGS model. © 2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75800
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
There are no files associated with this item.
作者单位: Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA, United States; Department of Earth Sciences, ETH Zürich, Zürich, Switzerland; Seminar for Applied Mathematics, Department of Mathematics, ETH Zürich, Zürich, Switzerland; Department of the Geophysical Sciences, University of Chicago, Chicago, IL, United States
Recommended Citation:
Pressel K,G,, Mishra S,et al. Numerics and subgrid-scale modeling in large eddy simulations of stratocumulus clouds[J]. Journal of Advances in Modeling Earth Systems,2017-01-01,9(2)