DOI: 10.1002/2015MS000532
Scopus记录号: 2-s2.0-84959481384
论文题名: Modifications to WRF's dynamical core to improve the treatment of moisture for large-eddy simulations
作者: Xiao H ; , Endo S ; , Wong M ; , Skamarock W ; C ; , Klemp J ; B ; , Fast J ; D ; , Gustafson W ; I ; , Jr ; , Vogelmann A ; M ; , Wang H ; , Liu Y ; , Lin W
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2015
卷: 7, 期: 4 起始页码: 1627
结束页码: 1642
语种: 英语
英文关键词: Boundary layers
; Clouds
; Moisture
; Sensitivity analysis
; Weather forecasting
; Cloudy boundary layers
; Compressible system
; Dynamic cores
; LES
; WRF
; Large eddy simulation
; boundary layer
; large eddy simulation
; mixing ratio
; numerical model
; potential temperature
; pressure gradient
; stratocumulus
; water vapor
英文摘要: Yamaguchi and Feingold (2012) note that the cloud fields in their large-eddy simulations (LESs) of marine stratocumulus using the Weather Research and Forecasting (WRF) model exhibit a strong sensitivity to time stepping choices. In this study, we reproduce and analyze this sensitivity issue using two stratocumulus cases, one marine and one continental. Results show that (1) the sensitivity is associated with spurious motions near the moisture jump between the boundary layer and the free atmosphere, and (2) these spurious motions appear to arise from neglecting small variations in water vapor mixing ratio (qv) in the pressure gradient calculation in the acoustic substepping portion of the integration procedure. We show that this issue is remedied in the WRF dynamical core by replacing the prognostic equation for the potential temperature θ with one for the moist potential temperature θm=θ(1 + 1.61qv), which allows consistent treatment of moisture in the calculation of pressure during the acoustic substeps. With this modification, the spurious motions and the sensitivity to the time stepping settings (i.e., the dynamic time step length and number of acoustic sub-steps) are eliminated in both of the example stratocumulus cases. This modification improves the applicability of WRF for LES applications, and possibly other models using similar dynamical core formulations, and also permits the use of longer time steps than in the original code. © 2015. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75944
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: Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Wash., United States; Brookhaven National Laboratory, Upton, NY, United States; National Center for Atmospheric Research, Boulder, Colo., United States
Recommended Citation:
Xiao H,, Endo S,, Wong M,et al. Modifications to WRF's dynamical core to improve the treatment of moisture for large-eddy simulations[J]. Journal of Advances in Modeling Earth Systems,2015-01-01,7(4)