气候变化领域集成服务门户(CCPortal): Impact of Urban Roughness Representation on Regional Hydrometeorology: An Idealized Study

CCPortal

DOI	10.1029/2020JD033812
	Impact of Urban Roughness Representation on Regional Hydrometeorology: An Idealized Study
	Li Q.; Yang J.; Yang L.
发表日期	2021
ISSN	2169897X
卷号	126 期号:4
英文摘要	Mesoscale climate models provide indispensable tools to understand land-atmosphere interactions over urban regions. However, uncertainties in urban canopy parameters (UCPs) and parameterization schemes lead to degraded representation of the drag effect in complex built terrains. In particular, for the widely applied single-layer urban canopy model (SLUCM) coupled with the Weather Research and Forecasting (WRF) model, near-surface horizontal wind speed is known to be overestimated systematically. In this study, idealized large eddy simulations (LES) and WRF-SLUCM simulations are conducted to study the separate effect of UCPs and aerodynamic parameterization on atmospheric boundary layer processes and rainfall variabilities in Phoenix, Arizona. For LES that explicitly resolves surface geometry, significant differences between three-dimensional (3D) versus two-dimensional (2D) representation of urban morphology are found in the surface layer and above. When surface drag is parameterized following SLUCM, surface morphologies have little impacts on the mean momentum transfer. WRF-SLUCM simulation results, incorporated with 3D urban morphology data, indicate that simply refining the frontal area index will reduce the surface drag, which further amplifies the systematic positive bias of SLUCM in predicting horizontal wind speed. Replacing the drag parameterization in SLUCM by LES-based aerodynamic parameters has evident impacts on near-surface wind speed. The impact of urban roughness representation becomes the most evident during rainfall periods, due to the important role of surface drag in dictating moisture convergence. Our study underlines that apart from intensive efforts in obtaining detailed UCPs, it is also critical to enhance the urban momentum exchange parameterization schemes. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	aerodynamic parametrization; large eddy simulation; urban canopy parameter; urban surface roughness
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185449
作者单位	School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, United States; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong; School of Geography and Ocean Science, Nanjing University, Nanjing, China
推荐引用方式 GB/T 7714	Li Q.,Yang J.,Yang L.. Impact of Urban Roughness Representation on Regional Hydrometeorology: An Idealized Study[J],2021,126(4).
APA	Li Q.,Yang J.,&Yang L..(2021).Impact of Urban Roughness Representation on Regional Hydrometeorology: An Idealized Study.Journal of Geophysical Research: Atmospheres,126(4).
MLA	Li Q.,et al."Impact of Urban Roughness Representation on Regional Hydrometeorology: An Idealized Study".Journal of Geophysical Research: Atmospheres 126.4(2021).