Abstract : 2G.15
The observational analysis of Tibetan Plateau vortex activity that induced flood in China

Yu Shuhua, Wenliang Gao
Institute of Plateau Meteorology,CMA.Chengdu

Some Tibetan Plateau vortices can move out of the main Plateau region that leads to the storm rainfall and torrential storm rainfall over a large area of China. Some of them even influenced the Korea peninsula and Japan.

Using synoptic and statistic methods with Tropical Rainfall Measuring Mission-TRMM data, the activity of the low vortex moving out of the Tibetan Plateau is analyzed. Some new findings on the characteristics of the main activity period of time, the vortex source regions and the trajectory of the Plateau vortex are obtained, as well as several new observational facts of the variability of the vortex after moving out of the Plateau. It is revealed that the characteristics of a vortex moving out of Plateau are different from those of a vortex that is active within the Tibetan Plateau. The results indicate:

1.The main period of time that the vortex moving out of the Tibetan Plateau influenced east China region weather is during June to August and they have different activities with the vortexes moving in the Tibetan Plateau and the southwest low vortexes.

2.The vortex moving out of the Plateau original source is close to Qumalai and Dege, which is different with the form source of the low vortex over the Plateau.

3.The tracks of the vortex moving out of the Plateau are usually moving toward with the trough to east or southeast direction, which is different with the vortexes over the Plateau move with the shear line to northeast direction.

4.The characteristic and intensity of the vortex will change after moved out of the Plateau. After moved out of the Plateau, they are mostly baroclinic low vortex and will be strengthened.