一次强对流天气的数值模拟和风场结构分析

Numerical simulations and wind field analysis of severe convective weather

利用数值预报模式WRF3.3和1°×1°的NCEP气象再分析资料,对2012年4月27日发生在白云机场的一次强对流天气过程进行了数值模拟,模拟中采用三层嵌套的方式,利用可视化工具GRADS对模式输出的模拟结果进行研究分析。结果表明:WRF模式能较好地模拟出此次强对流天气过程,低空950 hPa的中尺度正涡辐合中心与高空200 hPa的中尺度负辐散中心的相互耦合,能量相互释放是强对流天气得以维持和发展的重要原因;强天气威胁指数大小在某种意义上能够良好地反映出强对流天气发生的强弱程度。

A severe convective weather occurring at the Baiyun Airport on Apirl 27, 2012 is simulated by using WRF3.3 （Weather Research and Forecasting Model, Version 3.3） and NCEP （National Center of Environment Predicting）, meteorological data with l^x l^grid are reanalyzed, making a deep diagnostic analysis with three nested simulation and visualization tools GRADS. The results show that there is a strong simulating ability for the severe convective weather process by WRF. It is important for this weather that the 950 hPa mesoscale eddy convergence center couples mutually with the 200 hPa mesoscale negative divergence center, energy is interchanged between each other. Compared with the different resolution wind field data, there is a greater impact at the lower atmosphere as improving the resolution; there is a certain degree of positive correlation between the size of severe weather threat index and the occurrence of severe convective weather.