急流次级环流对陕南一次特大暴雨过程的作用

The Effect of Jet Sub-circulation on a Heavy Rain Occurred in Southern Shaanxi

对2003年7月15日陕西宁强一次特大暴雨过程进行分析,结果表明:导致宁强特大暴雨的中-α尺度对流云团,呈圆形或椭圆形,生命史为17 h;850 hPa低层水汽辐合对特大暴雨的贡献超出了700 hPa西南急流;急流次级环流提供的持续强劲上升运动是中-α尺度对流云团维持的主要原因。

The heavy rain process occurred on July 15 in 2003 in Ningqiang of Shaanxi province was analyzed. Results show that the meso -α - scale convective cloud cluster resulting in this heavy rain were elliptic or round and lasted for 17 hours, and the contribution of vapor convergence at the level of 850 hPa was more important than that of southwest jet on 700 hPa to the heavy rain, and the contin- uous and powerful updraft supplied by the jet sub - circulation was main cause for maintaining of the meso -α - scale convective cloud cluster.