高级检索

不同分辨率和云微物理方案对四川盆地 一次暴雨过程模拟的影响分析

Analysis of the Influence of Different Resolution and Cloud Microphysical Schemes on a Rainstorm Process Simulation in the Sichuan Basin

  • 摘要: 本文以美国国家环境预报中心(NCEP,National Centers for Environmental Prediction)的GFS(Global Forecast System)全球数值天气预报产品作为模式预报初始场,利用区域中尺度预报系统CMA-MESO(China Meteorological Administration Mesoscale Model)(原GRAPES_MESO)5.1版本对2021年9月3~5日发生在四川盆地的一次暴雨过程,采用3种不同分辨率(1 km、3 km、10 km)和2种云微物理参数化方案(WSM6、Thompson)设计5组试验进行数值模拟研究,结果表明:(1)试验模拟雨带与实况基本一致,但强降水时间、降水落区和降水强度与实况存在差异。随着降水阈值的提高,TS评分下降同时Bias变幅增大,空报率和漏报率也随之增加。(2)同分辨率是否采用积云参数化方案与同分辨率采用不同微物理方案对水汽通量模拟结果差异不大;5组试验在各自模拟的暴雨区均对应强烈的上升气流,且模拟强度均随分辨率提高而增大。(3)1 km分辨率下采用不同云微物理方案模拟液态粒子结果差异不大,但固态粒子明显不同。(4)3 km分辨率下加入积云参数化方案后,对于强降水中心的模拟结果存在较大偏差。整体而言,针对此次降水过程的各个试验模拟结果表明,在高分辨率条件下,Thompson方案饱和调整方案效果略好于WSM6方案,1 km_thompson方案对雨带刻画更精准,降水模拟最优。

     

    Abstract: This study uses the global numerical weather forecast product from GFS (Global Forecast System) of NCEP (National Centers for Environmental Prediction) as the initial field for model forecasting. The regional mesoscale forecast system, China Meteorological Administration Mesoscale Model (CMA-MESO) version 5.1 (formerly GRAPES_MESO), is used to analyze a rainstorm event that occurred in the Sichuan Basin during 3–5 September 2021. Five sets of experiments are designed, using three different resolutions (1 km, 3 km, and 10 km) and two cloud microphysical parameterization schemes (WSM6 and Thompson) for numerical simulations. The results indicate that: (1) The simulated rain belt generally aligns with the actual situation, but discrepancies in the timing, area, and intensity of heavy rainfall are observed. As the precipitation threshold increases, the TS score decreases, whereas the bias amplitude increases, leading to higher rates of false and missed reports. (2) No significant difference is observed in the simulation results of water vapor flux between the same resolution cumulus parameterization scheme and different microphysical schemes. The simulated rainstorm regions across all five experiment groups exhibit strong updrafts, and the simulation intensity increases as the resolution increases. (3) The simulation results for liquid particles are similar across different cloud microphysics schemes at the 1-km resolution. However, the results for solid particles show notable differences. (4) When the cumulus parameterization scheme is applied at the 3-km resolution, a large deviation in the simulation results of the heavy precipitation center is found. Overall, the experimental simulation results of the precipitation process indicate that under high-resolution conditions, the Thompson scheme’s saturation adjustment scheme is slightly better than that of the WSM6 scheme. Moreover, the 1 km_thompson configuration provides the most accurate depiction of rain belts, yielding the best precipitation simulation.

     

/

返回文章
返回