WRF模式中微物理和积云参数化方案的对比试验

为了研究微物理参数化方案对珠江三角洲(简称珠三角)降水模拟的影响,利用WRF中尺度数值预报模式,在3 km模式分辨率下,在微物理方案为WSM6方案条件下,选用KF、BMJ、GD以及G3等四种积云参数化方案对2010年5月14日广东珠三角地区的一次暴雨过程进行了模拟试验。结果显示,KF方案对于降水带和降水量的模拟与实况较为一致。在积云参数化方案为KF条件下,分别选用Kessler、Lin et al、WSM 3、WSM5、Ferrier(New eta)和WSM6等6种微物理方案再次对这次暴雨过程进行模拟试验,模拟结果的对比分析表明:选用Lin et al微物理方案时,模式较好地模拟出了强降水雨带的位置和降水强度;而其他5种参数方案的模拟效果均不好,降水量明显偏小,雨带位置偏差较大;同时对低空急流、K指数和上升速度等物理量分析可知,Lin et al方案能较好地模拟出降水实况。

THE EFFECTS OF DIFFERENT PHYSICS AND CUMULUS PARAMETERIZATION SCHEMES IN WRF ON HEAVY RAINFALL SIMULATION IN PRD

In order to study the impact of the parameterization schemes in the WRF model on rainstorm simulations,a heavy rainfall on 14 May 2010 in Pearl River Delta(PRD),Guangdong province is simulated.The study was carried out with four cumulus parameterization schemes(KF,BMJ,GD and G3) and six physics parameterization schemes(Kessler,Lin et al,WSM 3,WSM5,Ferrier(New eta) and WSM6 scheme) under a horizontal resolution of 3km.The results indicated that the Lin et al scheme,coupled with the Kain-Fritsch(KF) scheme,can accurately simulate the location and intensity of the heavy rainfall.However,the other schemes deviated in the location and produced less rainfall.The results of an analysis of unstable stratification and vertical convection velocity also indicated that this scheme can accurately simulate the reality of the rainfall.Generally,when coupled with the Kain-Fritsch(KF) scheme,this scheme is more accurate in simulating rainstorms in the PRD.