对流边界层发展受覆盖逆温影响的大涡模拟研究-气象科学.PDF

30 5 Vo.l 30, No. 5 2010 10 SCIENT IA M ETEOROLOG ICA SIN ICA O ct. , 2010 , . . , 20 10, 30( 5) : 715723. W an ing, Sun iann ing. Im pact of capping inversion on developm ent of convective boundary layer: evaluating the param eter ization of entrainm ent rate through largeeddy smi u lation. Scien tia M eteorolog ica S inica, 20 10, 30( 5): 715723. 万 静 孙鉴泞 ( , 210093) 本文运用大涡模拟方法研究了存在覆盖逆温时对流边界层顶部的夹卷过 特征, 并 通过敏感性试验着重分析了在此情况之下的夹卷速度参数化问题, 以及风切变的作用模拟结果 表明, 初始覆盖逆温改变了夹卷层的结构特征, 使得夹卷层结构参数明显增大, 风切变使这一效应 略有增强, 以往关于夹卷速度的参数化方案不再适用分析研究表明, 在有覆盖逆温的情况下, 夹 卷层结构参数是控制夹卷速度的关键因子, 应该将夹卷层结构参数作为变量引入夹卷速度参数化 方案, 该方案能够很好地预报出受覆盖逆温影响的对流边界层的发展过 P264 A Im pact of capping inversion on developm ent of convective boundary layer: evaluating the param eterization of entrainm ent rate through largeeddy simulation W an J ing Sun J iann ing (School of A tmospheric Sciences, Nanjing University, N anjing 210093, Ch ina) Abs tract In th is study, largeeddy smi ulation ( LES) is em ployed to investigate the mi pact of cap p ing inversion on the developm ent of convective boundary layer ( CBL) . The smi u lation resu lts show that the structure of en trainm ent zone is sign if icantly changed by the initial capping inversion. The stronger the initial capping inversion is, the larger the structure param eter is. A nd th is effect is slightly en hanced by the w ind shear. The prev ious param eterization schem es for the entrainm ent rate can not de scribe the developm ent of CBL satisfactorily. Analyses ind icate that in this si