“049”川渝暴雨的Q矢量与湿位涡分析  

Q Vector and Moist Potential Vorticity Analysis for the Heavy Rainfall in September 2004 in Sichuan and Chongqing

作　　者：段海霞[1] 陆维松[2] 毕宝贵[3] 

机构地区：[1]中国气象局兰州干旱气象研究所 [2]南京信息工程大学大气科学学院,江苏南京210044 [3]中国气象局国家气象中心,北京100081

出　　处：《南京气象学院学报》2007年第5期674-680,共7页Journal of Nanjing Institute of Meteorology

基　　金：干旱气象科学研究基金资助项目(TAMKY200603)

摘　　要：采用NCEP/NCAR再分析资料对"049"暴雨过程的准地转Q矢量及湿位涡进行诊断分析,揭示了暴雨期准地转Q矢量散度场、涡度场以及锋生函数的分布特征以及与暴雨之间的时空配置关系,指出了Q矢量散度与垂直运动有很好的配置关系,低层Q矢量辐合有利于上升运动的发展和维持,Q矢量对此次暴雨过程具有一定作用;暴雨区对流层中低层的对流不稳定与条件性对称不稳定对此次暴雨过程起了关键作用,而且很可能是中尺度对流系统发生发展的重要条件之一。Using the NCEP/NCAR reanalysis data, the quasi-geostrophic vector Q and moist potential vorticity analyses for the heavy rainstorm in September 2004 in Sichuan and Chongqing are performed, and the distributions of quasi-geostrophic Q-vector＇ s divergence, vorticity and the frontogenesis function, as well as their temporal/spatial relations with the heavy rain revealed. It is found out that there are close relationship between Q-vector divergence and vertical motion. The Q-vector convergence in the low level was of benefit to the development and maintenance of vertical motion and the rainstorm＇ s occurrence. Conditional symmetry instability and convective instability in the mid-low level played important role in the rainstorm and therefore are probably one of important conditions to the genesis and development of the mesoscale convective system.

关 键 词：Q矢量 湿位涡 对流不稳定 条件性对称不稳定 

分 类 号：P458.121.1[天文地球—大气科学及气象学]