Comparative Analysis of Precipitation Mechanism of Two Westward Typhoons Affecting Low-latitude Plateau

Based on surface observational data,TBB data of FY-2 satellite and reanalysis data of NCEP( 10 × 10,4-times-a-day's),the causes of heavy rainfall induced by No. 1002 typhoonCONSONand No. 1003Chanthuentering low latitude plateau,and their maintaining mechanisms on land were compared and analyzed. The results showed that origins and landing locations of two typhoons were different,but both of them carried vapor. There was southwest jet from Bay of Bengal beforeCONSONentering Yunnan,strong vapor convergence areas appeared at west of Typhoon depression and southwest jet zone,and strong rainfall areas were in correspondence with the center of moisture convergence. The southerly jets,existed at east of typhoon depressions before and after these two typhoons landing,were important for maintaining typhoon depressions. The southwest jet from Bay of Bengal was beneficial to strengthening and maintaining of CONSONtyphoon depression. The important reasons of typhoon No. 1002CONSONand No. 1003Chanthuafter entering low-latitude plateau maintained for a long time were higher-energy environment of low-latitude plateau,terrain dynamic effect,symmetric low pressure,temperature and humidity of typhoon.