Characteristics Of Southwest Vortex Activity And Diagnostic Analysis Of High Impact Vortex

Based on the statistical analysis of the activity characteristics of the Southwest Vortexes, Using the ERA-interim reanalysis data from1979to2011,time resolution was6h and spatial resolution was1°×1°.The result showed that the annual generated number of southwest vortex was59,more in1980,1989,1992,1997and2009,that average was69, less in1981,1990,1996and2006,that average just was51.The maximum number generated in the spring, followed by summer, at least in the fall and winter. Maximum number of vortex generated in June and March, followed May, Vortex generated more than the average number five in July,September,October. Relatively less in January, August, November and December.The number of vortex generated at least in November.Although the number of generated Vortex gradually decrease in the spring, summer, autumn, winter, the number of the Moving Vortex did not show a decreasing trend in turn each season. Instead of up to the summer, second with spring, autumn and winter least. For purposes of moving rate,summer reached44.1%,27.6%in spring,22.6%in fall, at least in winter justl1.3%. Basically the short lifetime Vortex in the spring,autumn,winter. In the summer, the long lifetime of Vortex have a higher proportion.Maintained a longer lifetime of the moving Southwest Vortexes had a total of126in the summer and showed northeastern(most), eastern, southeastern(least). In addition to being the East outward, showed an increasing trend to the northeast and southeast of the number of moving vortex with decadal variability.Meanwhile, diagnostic analyse the water vapor transport features and The contribution of condensation latent heat of the Southwest Vortex form8june to11june2013. The characteristics of the process of the southwest vortex activity is:in the southeast path to move, the cloud cluster very powerfull, cloud top height as the typhoon. Low vortex is developing very quickly. Result in southwest and south China a wide range of heavy rain weather. The main water vapor warm moist air flows from the Indian summer monsoon during the period of low vortex activities, southwest monsoon circulation provide warm, moist water environment in southwest region, the north cold air intrusion to make changes in temperature air meet up to produce precipitation, along with the release of condensation latent heat of low vortex generation. Cold air from the lower first started to enter the low vortex, resulting in lower tongue is cold, cold air invading, die filling system. Condensation latent heat releasing heat mainly located in the middle troposphere atmosphere, and the low vortex generated in the condensation latent heating para vortex disturbance positive contribution to the area, and the moving locus, tend to be is contribution to the area. While,in the lower troposphere,low vortex generated negative contribution to disturbances in the condensation latent heating para vortex area, and the moving locus, tend to be negative contribution to the area.Condensation latent heat release can cause low vortex formation, low vortex generated after the moving direction of the main affected by large scale circulation background field, but the movement is hot.