Analyese on A Heavy Rain Process on the East Side of Qinghai-Xizang Plateau

Using the hourlysatellite images and physical quantity field data, the cloud characteristicand physical structure for the heavy rain in Sichuan basin on the east side of Qinghai-Xizang Plateau during 8~9 June, 2002 are analyzed. The results show that the heavy rain was caused by two mesoscale convective storm complexes(MCC) in occurring the environment of warm and wet, and it is found that there is the dynamical structure of upper-level strong divergnce (negative vorticity) and low-level convergence (positive vorticity) in physical field. The development and maintenance of the MCC and heavy rainwere closely related to the superposition by the asending branchs of the direct circulation in the entrance region of upper-level jet and the secondary circulation in the exit region of low-level jet.