风廓线雷达在强降水监测预警中的应用研究

The application of wind profiler radar in the mornitoring and warning of heavy rainfall events

本文在风廓线雷达观测风场的基础上发展了低空风切变指数、高低空急流指数和温度平流三种产品算法，并将其用于两次强降水过程的监测预警研究。通过分析强降水发生前后风廓线雷达二次产品的变化得出：低空风切变指数在降水开始和结束时均会出现较大幅度的增长；低空急流指数一般在降水前3~4个小时开始增强，降水减弱时则大幅减小；高空急流指数在降水前2个小时左右会出现小幅的波动；此外，高低层冷暖平流强度和厚度的变化与降水过程也有很好的对应关系。

In this study,products of low-level wind shear index,upper and lower-level j et stream index and temperature advection which based on wind profiler radar observation are developed and introduced.Two severe pre-cipitation events were selected to study the tendency of three newly developed indexes before and after the precipitation.The results show that the low-level wind shear index increased at the beginning and the end of the pre-cipitation which is helpful in monitoring the rainfall;the low-level j et stream index usually increased sharply 3 to 4 hours before the precipitation and decreased as the rainfall dissipating.For the upper-level j et stream index,a fluctuation was found usually 2 hours before the precipitation.For the temperature advection,it was found that the variation of warm and cold advection thickness and intensity in the upper-and lower level is highly related to the evolution of the rainfall process.