一次引发重庆大暴雨的西南低涡动力诊断分析

利用2011年6月16日-18日期间逐6h、0.5°×0.5°NCEP/NCAR的GFS再分析资料,对一次引发重庆大暴雨的西南低涡进行动力诊断分析,结果表明:1)散度项的配置与平流项基本相反,散度项对低层西南低涡的发展和维持起主导作用,扭转项对西南低涡的形成也有重要贡献,平流项和摩擦耗散项是西南低涡涡度消耗的主要项,不利于西南低涡的生成发展.2)西南低涡发展维持的涡动动能主要源于水平通量散度项和涡动动能制造项,摩擦耗散项和垂直通量散度项是其主要消耗项.

Dynamic Diagnosis of a Southwest Vortex Inducing a Heavy Rainfall Over Chongqing Area

Using the NCEP/NCAR 0.5°×0.5° GFS (Global Forecast System) reanalysis data from June 16 to June 18 in 2011, dynamic diagnosis was made of the Southwest Vortex inducing a heavy rainfall over Chongqing area. Vorticity budget equation diagnosis showed that the divergence term played a leading role in the development and maintenance of the Southwest vortex. The advection term and dissipation term were the main consumption items of the Southwest vortex. Eddy kinetic energy budget equation diagnosis indicated that the eddy kinetic energy for the development and maintenance of Southwest vortex mainly came from the horizontal flux divergence term and the generation term of kinetic energy, and that the dissipation term and the vertical flux divergence term were the main consumption items of the Southwest vortex.