边界层廓线形状指数对一次江淮暴雨的模拟影响分析OA

Based on the WRF model and using a Jianghuai heavy rainfall event in 2022 as a case study,this study analyzed the impact of the boundary layer profile shape parameter(p)in the YSU boundary layer scheme on the precipitation simulation.Results show that the precipitation bias and TS scores differ significantly among the five simulation experiments with different p values(p=1.333,1.667,2.000,2.333,2.667).Reults show that TS,BIAS scores,correlation coefficients,and error analysis perform optimally overall at p=2.333.During the initial simulation stage,wind,temperature,and moisture exhibit clear linear relationships with p values:in the upper boundary layer,larger p values correspond to weaker vertical mixing,stronger wind speeds,higher temperatures,and lower specific humidity,while the opposite occurs in the lower boundary layer.During precipitation stage,the smaller the p value,the more homogeneous the mixing within the boundary layer,and the smaller the wind shear and vertical velocity,which is not conducive to the rise of water vapor and the development of convective activities.Compared with the plains,the mountainous underlying surface is more affected by the p value.