Circulation characteristics of two cases of Sea-entering Tibetan Plateau Vortices causing obvious differences in China precipitation

By using the NCEP FNL, historical synoptic charts and the year books of Tibetan plateau vortex and shear Line, based on synoptic and diagnosis methods, the observation facts of the sea-entering Tibetan Plateau vortices (STPVs) from 1998 to 2018, (STPVs) from 1998 to 2018, the two southeast-path STPVs that made great differences in precipitation are comparatively analyzed. The results show that: (1) The would bring precipitation to the eastern coast of China, and further affecting Korean Peninsula, Japan and Russia. (2) The different circulation characteristics of large- and small-scale precipitation STPVs are as follows:there are strong north and south branch jets at 200hPa and the north branch jet extends to east-ward with the core moving to east, and the circulation is more stable at 500hPa to the north of 45°N in East Asia, and STPV induces low vortex in the lower atmosphere in large-scale precipiitation STPV process. The opposite situation is true for small-scale precipitation STPV process. As a result, there are rising motion areas with large range and strong strength in and near the large-scale precipitation STPV area in the middle and lower troposphere, where larger water vapor flux and strong water vapor flux convergence also exist.