利用区域气候站逐时降水实况资料和NCEP1°×1°的6h全球再分析格点资料,运用WRFV3.2模式,采用不同积云对流和微物理参数化方案组合对2012年6月4—5日发生在酒泉地区的暴雨过程开展了敏感性试验。从降水量和降水落区等方面对各方案组合的模拟效果进行对比分析发现:选择不同的方案组合,可以不同程度地模拟这次暴雨过程的落区范围和降水量,微物理方案的选择对模拟结果的影响较积云对流方案更敏感。18km水平分辨率下,BMJ-WSM5方案组合模拟效果最优。通过对垂直速度、涡度、散度和雨水混合比等物理量的诊断分析,可以更好地理解不同积云对流和微物理参数化方案对暴雨预报的影响。
In order to investigate the influence of various parameterization schemes in different physical process- es on rainstorm simulation, the numerical simulation and a series of sensitive experiments are carried out to the typical heavy rainstorm in Jiuquan of Gansu province on June 4 - 5 2012 by using the Weather Research and Forecasting Model (WRFV3. 2) with a series of cumulus parameterization scheme and microphysics scheme combination. The study is performed by using the meteorological observational data and the FNL1°×1° six hours reanalyzed data. Comparison and analysis research of different scheme combinations' simulating effect is given in this paper, and the contrastive analysis is made with precipitation and rainfall area. The results show that, WRF has a strong simulating ability for precipitation and flow field variation as well as has a good capaci- ty to predict the mesoscale weather systems. The extended directions of rainstorm belts has been simulated accu- rately by all the scheme combinations, but the positions of the heavy rainfall centers souther than the reality. The sensitivity of microphysics schemes to the rainfall simulation was significantly higher than that of cumulus pa- rameterization schemes. The simulations were closer to the reality with 18 km fine horizontal resolution. In gen- eral, Betts-Miller-Janjic and WRF-Single-Moment-5-class (BMJ-WSMS) schemes performed better. ETS skill score confu-med that as well. WRF can also well simulate physical quantity fields of this rainstorm. The diagnos- tic analyses of vertical speed, vorticity, divergence, and the rain mixing ratio are carried out, then, the role of the cumulus parameterization schemes and microphysical schemes in rainstorm forecast can be better understood. These sesults will be beneficial for finding out the causes for rainstorm.