Abstract:
Based on ERA5 reanalysis data and TMPA V7 precipitation data, the spatial and temporal distribution, movement and precipitation characteristics of two types of southwest vortexes from 2010 to 2019 are statistically analyzed. Results indicate that the annual average of non-moving-out southwest vortices was 69 and the annual average of moving-out southwest vortices was 20. The primary genesis region of moving-out southwest vortex is Sichuan Basin and non-moving-out southwest vortex has two main sources, Sichuan Basin and Jiulong genesis region. Both types of southwest vortex are productive in spring and summer and less in fall and winter. The season difference of non-moving-out southwest vortex genesis is more significant, the genesis of moving-out southwest vortex in spring and summer is three times than that in fall and winter. Southwest vortex is mainly generated at night, most of southwest vortex generated during daytime are moving-out southwest vortexes. The average durations of two types southwest vortex are 15.4h and 39.6h. The moving-out southwest vortex mainly moves eastward and it travels longer in spring and summer . Its speed is largest in winter and smallest in summer. The precipitation intensity of moving-out vortex is stronger than non-moving-out vortex. Non-moving-out southwest vortex is mainly with light precipitation. The moving-out southwest vortex is always along with heavy precipitation.