摘要
近地面风场与人类生活密切相关,精细准确的风场模拟可以为气象实况产品提供数据支撑。目前,中尺度模式的时空分辨率无法满足局地精细化模拟的需求,因此本研究基于中尺度模式(WRF)内层嵌套大涡模拟(LES),采用五层双向嵌套在门头沟东部区域展开百米近地面风场模拟。结合地面观测,设计边界层和亚网格模型敏感性试验,对比1 km分辨率下YSU和LES边界层方案对里层嵌套的影响,检验和评估不同亚网格模型在真实大气中的适用性。结果表明,在中微尺度过渡分辨率1 km开启YSU边界层较LES边界方案模拟效果更佳,在保持捕捉湍流细节的能力下,拥有较低的误差。不同的亚网格敏感性试验中,1.5TKE,SMAG,1.5TKE_NBA和SMAG_NBA四种亚网格模型差异较小,统计指标上,SMAG的均方根误差最低,相关系数最高。同时,四种亚网格模型依旧存在模式本身造成的高值低估,低值高估的现象,SMAG在风矢量分布和风速风向概率密度分布中与观测最为接近。在风场的瞬时空间分布上,SMAG_NBA表现出对细小的湍流捕捉能力的优势。
Human life is affected by the intensity of near-surface wind fields,so obtaining high-precision wind field meteorological live products is essential.Precise and accurate wind field simulation can provide data support for real-time weather products.At present,the spatial-temporal resolution of the mesoscale model is low,which cannot meet the requirement of local fine-scale simulation.In this study,based on the large eddy simulation(LES)nested in the medium-scale Weather Research and Forecast Model(WRF),we simulated the near-surface wind field in the eastern part of the Mentougou region,which has five layers of two-way nesting.Meanwhile,combined with ground meteorological observation,we designed sensitivity experiments of boundary layer and Subgrid-Scale(SGS)models to compare the effects of YSU and LES boundary layer schemes on inner layer nesting at 1 km resolution,and examined and evaluated the applicability of different SGS models in the real atmosphere.The results show that the YSU boundary layer can perform better simulation than the LES boundary scheme when turned on at the mesoscale transition resolution of 1 km,with fewer errors and the ability to capture turbulence details.In the different SGS models sensitivity experiments(1.5TKE,SMAG,1.5TKE_NBA and SMAG_NBA),there is little difference in the NBAs.SMAG had the slightest root-mean-square error and the highest correlation coefficient for statistical indicators.However,the wind speed simulation of four models still underestimates the high value and overestimates the low value.SMAG is closest to the observation in the wind vector distribution and probability density distribution of the wind.In the instantaneous spatial distribution of the wind field,SMAG_NBA shows a competitive advantage in capturing fine turbulence.
作者
李叶晴
师春香
沈润平
粟运
张德杰
葛玲玲
LI Yeqing;SHI Chunxiang;SHEN Runping;SU Yun;ZHANG Dejie;GE Lingling(College of Geographical Science,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;National Meteorological Information Center,Beijing 100081,China;College of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China)
出处
《高原气象》
CSCD
北大核心
2023年第3期758-770,共13页
Plateau Meteorology
基金
国家自然科学基金项目(92037000)。
