一次暖区强降水的热力动力条件

Thermodynamic Conditions of A Warm-Zone Heavy Rainfall Event

利用地面自动站观测资料、雷达资料和NCEP再分析资料,分析了2009年4月19日福建中南部强降水过程的热力动力条件。结果表明:这次降水过程具有明显的中尺度雨团特征,直接影响系统是地面中尺度辐合线;低空西南急流为暖区强对流发生、发展提供了必要的水汽条件;低层暖平流、高层冷平流的上下层配置,使不稳定能量得以聚集,为对流发展提供必要的能量。

By using the data from automatic ground stations, radar and NCEP reanalysis, the causes and thermodynamic conditions of a heavy rainfall event occurred in the central-southern Fujian on 19 April 2009 are analyzed. The results show that there were active mesoscale rain bands during this process; the mesoscale convergence zone at ground was a direct influencing factor; the southwest low-level jet provided water vapor for the occurrence and development of strong convection in the warm zone; the tow-level warm air advection and high-level cold air advection made unstable energy built up, and provided necessary energy for convection to develop.