江苏一次飑线初生的诊断分析与数值模拟

Diagnostic Analysis and Numerical Simulation for the Birth of Squall Line in Jiangsu

为研究飑线初生的原因,利用美国国家环境预报中心(NCEP)再分析资料、探空资料、多普勒雷达资料和数值模拟等手段,对2009年6月14日发生在江苏的一次飑线天气过程进行了详细分析。南京站及其上游的阜阳、安庆等站的温度-对数压力图揭示了对流层顶强降温的垂直结构有利于强对流天气的形成。通过分析NECP的物理量分布,发现江苏地区在飑线初生和发展中有较大的温度梯度、充沛的水汽输送和强辐合上升运动,飑线回波的初生具有典型特征。天气研究与预报(WRF)模式的模拟发现,起转延迟(spin-up)阶段之后,模式较好地模拟了飑线的初生发展。研究结果为深入认识飑线初生机理并改进预警提供了参考依据。

To understand the initiation of a squall line weather in Jiangsu,East China on June 14,2009,the National Centers for Environmental Prediction(NCEP)reanalysis data,sounding data,Doppler radar data,and numerical simulation were used for analyses.As shown in the temperature vs.logarithmic pressure diagram of Nanjing Station and its upstream stations,including Fuyang and Anqing,the vertical structure of strong cooling at the tropopause was beneficial to the formation of the strong convective weather.By analyzing the physical quantity distribution of NECP.It is found that there are large temperature gradients,abundant water vapor transport,and strong convergence upward motion in the initiation and development of the squall line in Jiangsu area,and the initial echo of squall line feature typical characteristics.The simulation of weather research and forecasting(WRF)model show that the model can simulate the birth of the squall line after the spin-up stage.The results provide a reference for further understanding the mechanism of squall line initiation and improving the early warning.