应用湿Q矢量诊断梅雨锋暴雨

Using the Wet Q-vector to Diagnose a Process of Meiyu Front Heavy Rain

利用湿 Q矢量 ,结合改进的 MM4 ( MMM4 )模式模拟输出的加密资料 ,细致地诊断分析了 1 991 - 0 7- 0 5T2 0— 0 6 T2 0一次典型的江淮梅雨锋暴雨过程。结果表明 :湿 Q矢量散度辐合场随高度向北倾斜 ;在梅雨锋暴雨发展、衰亡阶段 ,湿 Q矢量散度散、合场在垂直方向上主要呈现出了相间分布的特点 ;从湿 Q矢量散度辐合场这个角度探讨了梅雨锋暴雨的内在机理 ,并给出了梅雨锋暴雨具体预报的新思路。

Using the wet Q-vector and combining with the intense data output of the modified MM4(MMM4) model simulation,a typical Meiyu front heavy rain process occurred during 5-6th July 1991 in the Changjiang-Huaihe Basin is diagnosed carefully in this paper. The results are as follows:the convergence field of wet Q-vector divergence tilts northwards with height; the divergence/convergence fields of wet Q-vector divergence show an alternate distribution in the vertical direction at the developing and decaying stages of Meiyu front heavy rain; based on the convergence field of wet Q-vector divergence,the intrinsic mechanism of Meiyu front heavy rain is discussed, and a new thinking for the forecast of Meiyu front heavy rain is given.