城市形态参数对不同城市冠层方案热动力环境模拟的影响OA

The default urban morphology parameters in the WRF(weather research and forecasting)model are spatially homogenized and cannot adequately characterize the spatial heterogeneity of real urban underlying surfaces.To investigate the impacts of localized urban morphology parameters on thermodynamic environment simulations using different urban canopy schemes in the WRF model,this study takes the megacity of Guangzhou as a case study and conducts sensitivity experiments.The simulation performances of the single-layer urban canopy(UCM)and the multi-layer building effect parameterization(BEP)schemes for near-surface meteorological elements under the default and localized parameters settings are compared.The results show that:1)The optimization effects of the localized urban morphology parameters differ significantly between the two schemes.The most notable improvements are found in 2 m temperature for the UCM scheme and in 10 m wind speed for the BEP scheme,with bias reduction rates reaching 90.1%and 49.8%,respectively.More than 71%of stations exhibit improved performance in 2 m temperature simulations,and over 93%show enhanced capability in 10 m wind speed simulations.2)The localized urban morphology parameters lead to increases in simulated surface skin temperature in both schemes,with a more pronounced rise in the central urban area.Specifically,the BEP scheme demonstrates a greater temperature rise due to narrowed street canyons and enhanced heat trapping.The impact of these parameters on surface skin temperature is greater than that on 2 m temperature.3)Due to increased surface roughness induced by larger standard deviations of building height,the 10 m wind speeds in both schemes decrease by more than 0.8 m/s.These parameters cause the planetary boundary layer height to increase by 60-90 m in the UCM scheme,while it decreases by 10-30 m in the BEP scheme.These differences are closely related to changes in 2 m temperature and vertical turbulent momentum exchange.This study clarifies the response characteristics of different urban canopy schemes to urban morphology parameters,refines the localized application of these parameters in the WRF model,and provides technical support for high-resolution urban climate simulations.