梅雨锋暴雨的Q矢量定性分析

本文利用1991年7月5日20时－6日20时一次江淮梅雨锋暴雨过程实部资料，结合地面降水分析，定性地比较分析了准地转Q矢量、半地转Q矢量及湿Q矢量的诊断特性。结果表明，半地转Q矢量比准地转Q矢量优越。非地转Q矢量与湿Q矢量相差不大，都明显比半地转Q矢量及准地转Q矢量优越。准地转Q矢量表现最差；700hPa各Q矢量的辐合场较各自在850hPa及500hPa的相应场对降水的反映更好，尤其是700hPa非地转Q矢量及湿Q矢量辐合场与同时刻地面降水的发生有很好的对应关系；与降水对应的Q矢量的辐合场基本位于槽前及气旋的中、前方，这对台站实际业务预报工作有参考价值。

QUALITATIVE COMPARISON AND ANALYSIS OF Q-VECTOR

Employing data of a Meiyu front rainstorm during 5-6 July,1991,in the Changjiang-Huaihe Basins with the aid of surface precipitation distribution,the diagnostic characteristics of wet Q-vector (QV),quasi-,semi-and ageostrophic-QV are examined qualitatively on a vector field(VF)basis.The results show:as far as the diagnostic features of wet QV,quasi-,semi-and ageostrophic-QV are concerned,the third is superior to the second one, that is worst of all,and the first is almost the same as the last.Furthermore,they are advantageous over the second and the third obviously;the vector convergence field (VCF)at 700hPa of each QV is better than that of itself at 850hPa and 500hPa in reflecting precipitation,especially,the VCF at 700hPa of ageostrophic-and wet-QV have good indications to synchronous rainfall;the QV VCF corresponding to precipitation lies basically in front of a trough and in the middle or rear of a cyclone,which can act as a reference tool to operational job.