气候变化领域集成服务门户(CCPortal): An Orographic-Drag Parametrization Scheme Including Orographic Anisotropy for All Flow Directions

CCPortal

DOI	10.1029/2019MS001921
	An Orographic-Drag Parametrization Scheme Including Orographic Anisotropy for All Flow Directions
	Xie J.; Zhang M.; Xie Z.; Liu H.; Chai Z.; He J.; Zhang H.
发表日期	2020
ISSN	19422466
卷号	12 期号:3
英文摘要	Orographic drag is an essential process for numerical weather predictions in complex terrain regions, which depends on the inflow direction. In this study, we define the orographic asymmetry vector (OAV) for a coarse grid as the normalized vector between the grid's center point and its center of mass, and the orographic asymmetry in a flow direction—which describes the inclination direction and the extent of the subgrid terrain—is calculated as the projection of OAV on this direction. Calculations of the effective orographic length (OL) and the model grid length λ are extended to all flow directions. A new orographic drag scheme, which considers the effect of orographic anisotropy in all directions, is then developed based on the OAV projection and the extended OL and λ for any given direction. Sensitivity tests of the orographic drag under the new scheme are conducted using a 5 m/s vertically uniform wind along different directions for four coarse grid points in typical mountain regions. The new scheme is shown to provide a more continuous transition of the orographic parameters and the resulting stress as a function of flow direction than piecewise transition of schemes with only eight directions. The predicted momentum flux profile of the new scheme is compared with mountain-wave simulations obtained from the integrated modeling system IAP-WRF (Institute of Atmospheric Physics-Weather Research and Forecasting Model) for the Rocky Mountain. The new scheme is shown to predict an overall narrower stress scatter about the reference simulation than the old scheme. © 2020 The Authors.
英文关键词	Flow direction; mountain-wave simulation; Orographic anisotropy; Orographic asymmetry vector; Orographic drag
语种	英语
scopus关键词	Anisotropy; Drag; Landforms; Atmospheric physics; Continuous transitions; Integrated modeling system; Mountain regions; Numerical weather prediction; Parametrizations; Sensitivity tests; Weather research and forecasting models; Weather forecasting; anisotropic medium; anisotropy; complex terrain; mountain region; parameter estimation; simulation; weather forecasting; Rocky Mountains
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/156750
作者单位	State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; School of Marine and Atmospheric Sciences, State University of New York at Stony Brook, Stony Brook, NY, United States; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Xie J.,Zhang M.,Xie Z.,et al. An Orographic-Drag Parametrization Scheme Including Orographic Anisotropy for All Flow Directions[J],2020,12(3).
APA	Xie J..,Zhang M..,Xie Z..,Liu H..,Chai Z..,...&Zhang H..(2020).An Orographic-Drag Parametrization Scheme Including Orographic Anisotropy for All Flow Directions.Journal of Advances in Modeling Earth Systems,12(3).
MLA	Xie J.,et al."An Orographic-Drag Parametrization Scheme Including Orographic Anisotropy for All Flow Directions".Journal of Advances in Modeling Earth Systems 12.3(2020).