2004—07—16河南省特大暴雨过程螺旋度分析

应用螺旋度理论对2004年7月16～17日河南省特大暴雨天气过程进行了诊断分析。结果表明：螺旋度分布低层天气系统有很好的对应关系，暴雨过程中相对垂直螺旋度大值区长轴始终与低层南北向切变线走向一致；大暴雨区与低空水平螺旋度大值区长轴走向一致，且与水平螺旋度梯度≥130m．s^-2的区域基本对应；暴雨首先产生在高湿中心与不稳定能量中心相重叠区域，并随相对垂直螺旋度正值增大而增强，且与水汽输送区相对应。

Helicity Analysis on the Torrential Rain in Henan in July 16,2004

By using of the helicity theory, the torrential rain in Henan province during July 16-17,2004 was diagnosed. The analysis results show that the rainstorm is produced in higher temperature, higher humidity and unstable atmosphere. There is a higher relative vertical helicity(HR) in rainstorm area; The trend of the low-level vertical helicity is consistent with that of the precipitation. The variation of helicity indicates weather systems moving developing and falling area and intensity of torrential rain.Helicity also reflects the distribution of vertical moving and rotation status of atmosphere.