一次强烈发展西南低涡的中尺度结构分析

A CASE ANALYSIS ON MESOSCALE STRUCTURE OF SEVERE SOUTHWEST VORTEX

通过对１９８９年７月８～１０日发生于四川盆地东部的西南低涡的诊断分析，揭示了西南低涡成熟期的三维结构．结果表明，成熟阶段的西南低涡正涡度可伸展到１００ｈＰａ以上，中心轴线垂直；其流场和高度场表现为贯穿对流层的中尺度气旋和低压；涡区内动量、层结、垂直运动等呈非对称分布，是一个准圆形而非对称的中尺度系统．

iagnostic analysis on a case of southwest vortex over the eastern Sichuan basin in 8～10 July 1989 reveals its threedimensional structure in mature stage. The results show that the southwest vortex is a mesoscale cyclone and depression throughout the troposphere. Its cyclonic vorticity could vertically extend to 100 hPa, and center axis is nearly vertical. The distributions of momentum, stratification and vertical motion present asymmetry in the vortex.