基于中尺度数值模式 (WRF v3.4), 对发生在湖北省红安地区的一次强对流降水天气过程进行了数值模拟.结果表明, 此次强对流天气是在水汽充足, 高层辐散、低层辐合以及不稳定能量较大的条件下发生发展的.模式模拟得到的地面累积降水和雷达反射率因子与实况相符, 云下雨水蒸发过程显著.进行敏感性试验, 将雨水蒸发率分别降至1/2、1/4以及完全关闭后, 雷达回波强度减弱, 对流演变特征发生变化.蒸发过程的减弱使得降水始发阶段以及后期消散阶段的降水强度增强, 在对流旺盛阶段降水强度减弱.同时雨水蒸发过程减弱导致云中上升气流减弱, 冰雪晶及霰粒子含水量极大值减小、极大值所在高度降低.可见, 雨水蒸发对对流云团动力、热力结构及云微物理结构以及云物理过程均有一定程度的影响.%In this study, the severe convective rain process occurring in Hongan, Hubei Province is simulated using the Weather Research and Forecasting Model (WRF).The results showthat the severe convective weather developed under the condition of abundant water vapor, divergence in high-level, convergence in low-level, and unstable stratification.Simulated rainfall and radar reflectivity are in high agreement with the situation, and evaporation of raindrops is significant under the cloud.After the sensitivity experiments of reducing the evaporation of rainwater to half, quarter and zero, the radar reflectivity is weakened, and is shown to have great influences on the evolution of the convective process.The characteristics of the rain zone are similar to those of the original scheme, and the regional average precipitation is weakened.Reducing evaporation causes the precipitation intensity in precipitation initial occurrence stage and dissipation stage to be enhanced and weakened in the development of the precipitation process.At the same time, the weakening of the vertical airflowand reduction of graupel content are caused by the weakening of raindrop evaporation.In summary, the evaporation has an influence on the dynamics, thermal structures, cloud microphysical structures and processes of convective clouds.
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