一次暴雨天气过程的物理量分析

对2002年发生在闽东的一次暴雨天气过程进行分析。结果表明：螺旋度和对流有效位能对暴雨的预报有指示意义，暴雨产生在低层正螺旋度中心与高层负螺旋度中心相配合和中低层有不稳定能量储存的高能区。在暴雨强盛期，螺旋度呈中低层正值，高层负值的上下配置，最大值位于700hPa。对流有效位能大值区与暴雨中心相对应，对流有效位能的时空变化能较好地反映暴雨的时空演变特征。利用中尺度数值模式输出的结果对不稳定能量场进行分析表明，位势不稳定能量的释放是暴雨产生发展的可能机制之一。

Physics Parameters Analysis of a Heavy Rainfall Event

A heavy rainfall event in the eastern Fujian in 2002 is analyzed. The results show that helicity and CAPE are significant predictors to a heavy rainfall. The rainfall is generated where exist the positive helicity center at low-level and negative helicity center at high-level and high storage energy of potential instable at middle and low levels. The helicity is positive at upper levers and negative at low levels during the time of rainfall prosperity, and its maximum is at 700hPa. The high CAPE value is coincident with the center of the rainfall. The time and spatial variation of CAPE is well corresponding to that of rainfall. Based on the output of the mesoscale numerical model, the instable energy field is studied. It turns out that the release of potential instable energy may be one of mechanism for a heavy rainstorm genesis and development.