江淮切变线──梅雨锋次级环流的诊断研究

DIGNOSTIC STUDY OF SECONDARY CIRCULATION ACROSS JIANGHUAI WIND SHEAR LINE-MEIYU FRONT SYSTEM

本文利用推广的Sawyer－Eliassen锋面次组环流方程对一次江淮切变线──梅雨锋系统的次级环流进行了诊断研究，讨论了它的特征以及形成。发现各强迫项在不同地理位置所起的作用是不同的，所形成的环流特征也不同。高低空急流及凝结加热对次级环流的形成和加强起着重要作用。

The secondary circulation across the synoptic - scale wind shear line - - Meiyu front system is investigated using Sawyer- -Eliassen equation. A thermal direct circulation with warm air rising on the front zone and cold air sinking to the north of the front was found in the weak precipitation area. But in the heavy precipitation area, the secondary circulation presented two cells:one is the thermal direct to the north of the front and the other is the thermal indirect to the south of the front. The existence of a low level jet and a high leval and the release of latent heating play an important role in the formation and intensification of the secondary circulation