积云与微物理方案对山西南部暴雨预报的敏感性试验

A Sensibility Experiment of Different Cumulus Parameterization and Microphysics Schemes on Rainstorm Forecast in Southern Shanxi

利用WRF(Weather Research and Forecast system)中尺度数值模式,采用KF、BMJ、GF 3种积云对流参数化方案和WSM5、WSM6、WDM5、WDM6 4种微物理方案,对山西南部2007年7月29—30日的一次特大暴雨过程进行数值模拟与敏感性试验,并对不同积云方案和微物理方案的降水预报性能进行定量评估。结果表明:粗网格选用不同的积云对流参数化方案,可以对细网格强降水的落区预报产生较大的影响,GF积云方案能够合理地预报出主雨带、降水中心的位置和强度,选择适当的积云方案可以使强降水预报的TS评分提高0.19;不同微物理方案对强降水中心位置、强度、分散程度等的模拟结果有显著差异,WDM6微物理方案对于此次山西南部暴雨过程的模拟能力最好,尤其对于强降水预报具有明显优势。进一步分析表明:微物理过程中水相物质预报量的增加,可以改进模式的降水预报性能;综合考虑各种水相物质混合比和数浓度的双参数方案的计算过程更为精确,强降水预报能力更好,双参数方案较单参数方案的强降水TS评分可以提高0.08。

Based on WRF（Weather Research and Forecast system） mesoscale model, a heavy rainfall duringJuly 29-30, 2007 in southern Shanxi was simulated, and numerical sensitive experiments were carried out toevaluate 3 cumulus parameterization schemes and 4 microphysics schemes. The precipitation forecast withdifferent schemes was experimented contrastively and verified, and a preliminary evaluation was presentedwith regard to each scheme. The results indicated that： there were obvious differences in fine domain＇ssimulated precipitation location when different cumulus parameterization schemes were used in the coarsedomain, and the belt distribution and intensity of the simulated precipitation by GF cumulus scheme was closerto the fact than others. TS score of simulated strong rainfall could be improved by 0.19 with the appropriatecumulus scheme. Different microphysics schemes had a significant influence on the simulated position,intensity and dispersibility of heavy rainfall center, and WDM6 microphysics scheme had strong capacity thanothers to simulate this heavy rainfall. Further research demonstrated that the increase of mass variables in themicrophysics scheme could modify the numerical rainfall prediction performance, and double- momentmicrophysical schemes including number variables performed better in simulated precipitation, especially inthe TS score of heavy rain.