乌鲁木齐冬季冷锋云带和锋下层积云的微物理结构及其降雪特征

The microphysical structures and precipitation characteristics of the cloud zone,over a wintertime cold front and stratocumulus under it in Urumqi

本文根据1983年11月7日云物理专业考查飞机对乌鲁木齐冬季一次冷锋降水前期的云与降水微结构观测,进行了分析与研究,结果表明:在冷锋降雪初始阶段,云具有多层结构,锋上存在一条宽约5km的云带,估计云带中的上升气流大于0.8m·s^(-1),具有窄对流云带的某些特征。冰晶初始形成于温度为-17℃的锋上云带顶部。在锋上与锋下存在两个过冷水区,据此判断在冷锋降雪前期具有人工增雪条件。

The micro-physical structures of cloud and , snowfall in precipitation starting stage were observed with a instrument aircraft on Nov. 7, ,1,983. The results show that there were several cloud layers in the, starting .stage of cold front snowfall, and there was a snow band with 5 km .width over the cold front.It is estimated that the updraft velocity is greater than 0.8 m·s-1 in the snowband,which is somewhat characterized by a narrow con-vective cells band.The ice crystals were formed at the top of the convec-tive' cloud band with temperature about -17℃.