DOI: 10.1002/2017MS001092
Scopus记录号: 2-s2.0-85034213543
论文题名: Evaluation of WRF SCM Simulations of Stratocumulus-Topped Marine and Coastal Boundary Layers and Improvements to Turbulence and Entrainment Parameterizations
作者: Ghonima M ; S ; , Yang H ; , Kim C ; K ; , Heus T ; , Kleissl J
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2017
卷: 9, 期: 7 起始页码: 2635
结束页码: 2653
语种: 英语
英文关键词: Air entrainment
; Atmospheric thermodynamics
; Clouds
; Large eddy simulation
; Mixing
; Parameterization
; Turbulence
; Coastal
; Coastal boundary layers
; Liquid water content
; Planetary boundary layers
; Single-column model
; Stratocumulus
; Stratocumulus-topped boundary layers
; Yonsei University
; Boundary layers
; buoyancy forcing
; climate modeling
; cloud water
; energy flux
; entrainment
; inversion layer
; large eddy simulation
; moisture transfer
; parameterization
; stratocumulus
; turbulent boundary layer
; water content
英文摘要: Stratocumulus-topped boundary layers (STBLs) are notoriously difficult to parameterize in single-column models due to the strong inversion layer across which entrainment mixing plays an important role in modulating the boundary layer mass, energy, and moisture balances. We compare three different WRF planetary boundary layer (PBL) schemes (Yonsei University, YSU; Asymmetric Convective Model version 2, ACM2; Mellor-Yamada-Nakanishi-Niino, MYNN) against large eddy simulations (LES) to find out that they underestimate entrainment flux in stratocumulus over both ocean and coastal land. Hence, the PBL schemes produce a cooler, moister STBL with higher liquid water content. In order to improve the entrainment parameterization, we propose a modification to the YSU scheme that takes into account the in-cloud turbulence flux contribution to cloud top entrainment through the formulation of a velocity scale based on the in-cloud buoyancy flux. A revised top-down mixing profile is also implemented to model mixing due to turbulence generated by longwave cooling at the cloud top. The modified YSU simulates stronger entrainment flux, resulting in a STBL that matches LES results. Similar modifications were made to ACM2 in addition to implementing explicit entrainment, and while the results also showed good agreement with LES, discretization issues and conflicts with its original design prevent immediate implementation, as the contribution from the modifications and the original scheme are difficult to correctly modulate. © 2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75703
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: Center for Renewable Resources and Integration, Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA, United States; New and Renewable Energy Resource Center, Korea Institute of Energy Research, Yuseong-gu, Daejeon, South Korea; Department of Physics, Cleveland State University, Cleveland, OH, United States
Recommended Citation:
Ghonima M,S,, Yang H,et al. Evaluation of WRF SCM Simulations of Stratocumulus-Topped Marine and Coastal Boundary Layers and Improvements to Turbulence and Entrainment Parameterizations[J]. Journal of Advances in Modeling Earth Systems,2017-01-01,9(7)