Characteristics of urban atmospheric boundary layer over a Northwest valley city of China in summer based on WRF simulation
To improve the simulation of meteorological fields in the valley terrain,we used the fifth-gen-eration reanalysis data(ERA5)and global reanalysis data(FNL)as initial fields.Taking Tianshui City as the research object,compared the applicability of ERA5 and FNL reanalysis data in driving the weather research and forecasting model to simulate the urban boundary layer in a northwest valley and analyzed the characteristics of the atmospheric boundary layer during summer.The research results showed that,the simulated near-surface temperature,near-surface wind speed,wind direction,and relative humidity derived by ERA5 in the main urban area of Tianshui City showed a higher correlation with the observa-tions than that of FNL,especially for near-surface wind speed and wind direction,which had been im-proved by 25.4%and 70.0%respectively.The spatial distribution of meteorological fields in the main ur-ban area of Tianshui City exhibited obvious urban heat island effects and valley wind circulations,with a stronger urban heat island effect in the relatively open Maiji area.During daytime precipitation,the val-ley wind circulation and heat island effect weakened,and wind speeds within and around the valley were relatively small.In the main urban area of the city,there was a positive correlation between near-surface temperature and wind speed in summer,and a negative correlation with relative humidity.The bound-ary layer height showed significant diurnal variations,and the atmospheric stability was characterized by stable atmospheric stratification.
the fifth-generation reanalysis datariver valley urbanatmospheric boundary layerweather research and forecasting model
万方数据
维普
