摘要
利用NCEP逐日再分析值资料,分析了影响2005年6月25日长江流域暴雨过程的西南低涡结构特征及其移动发展机制。结果表明:25日移出川东影响长江中游的西南低涡是一个显著不对称的斜压系统,其发展过程中始终伴随着强盛的西南低空急流;低涡移动过程中非地转平衡性很强,高层正涡度平流和低层暖平流的共同作用,是低涡移动过程中周围大气维持较大的非热成风涡度,从而造成低涡区域上空强上升运动的重要原因。
Using the NCEP reanalysed daily data, we analysed the structure and developing mechanism of the southwest low vortex affecting the heavy rain along the Yangtze River valley on 25 June, 2005. The results indicated that the southwest low vortex was a prominent baroclinic system, and there was keeping the strong southwest lower jet in the southeast position of the moving low vortex. There were non-geostrophic balance in the low vortex area, the effects of the vorticity advection in upper level and the temperature advection in low level were the importance reason of maintaining the big non-thermal-wind vorticity, so caused strong ascending motion in the area of the low vortex.
出处
《高原气象》
CSCD
北大核心
2007年第1期197-205,共9页
Plateau Meteorology
基金
湖北省自然科学基金项目(CGZ0036)
中国气象局武汉暴雨研究所开放基金(IHR2005G04)共同资助
关键词
西南涡
低空急流
非地转平衡
非热成风涡度
Southwest vortex
Lower layer jet
Non-geostrophic balance
Non-thermal-wind vorticity
