WRF模式对山谷城市边界层模拟能力的检验及地面气象特征分析

Verification of WRF Simulation Capacity on PBL Characteristic and Analysis of Surface Meteorological Characteristic over Complex Terrain

利用先进的WRF中尺度模式中3种边界层参数化方案（YSU、MYJ和ACM2）,模拟了2005年1月25~28日兰州市冬季地面温度和风速的变化,并与同期系留探空和自动气象站的实测资料进行了对比分析。结果表明：对兰州冬季大气边界层地面温度日变化的模拟,局地闭合的MYJ方案优于非局地闭合的YSU和ACM2方案;3种方案模拟的夜间位温廓线较好,白天的较差;在边界层低层,考虑局地和非局地闭合的ACM2方案模拟的位温廓线与观测值比较一致;在边界层上部,局地闭合的MYJ方案则更适合于描述大气湍流对位温垂直分布的影响;3种边界层参数化方案模拟的兰州地区冬季温度场空间分布特征相似,但MYJ方案模拟的夜间温度低于YSU和ACM2方案,白天则高于YSU和ACM2方案。

Three planetary boundary layer（PBL） parameterizations（YSU,MYJ and ACM2） in WRF model are used to simulate surface temperature and wind in Lanzhou during 25~28 January 2005.Comparing with the simulations and the data from captive balloon sounding and Auto Weather Station,the results shows that：（1） Local MYJ scheme presents more reasonable diurnal changes of surface temperature than the other unlocal schemes（YSU and ACM2）.（2） As to the simulation of potential temperature profiles,the results at the nighttime are better than that in the daytime.In the low-layer PBL,the potential temperature profiles from local and unlocal ACM2 schemes give better agreement with the observation;while in the upper PBL,local MYJ scheme is more suitable for the simulation of vertical profiles for potential temperature.（4） The spatial distributions of temperature over Lanzhou in winter from three PBL parameterization schems are similar,while the temperature at the nighttime from MYJ scheme is higher than that from YSU and ACM2 schemes,but opposite in the daytime.