华北层状冷云降水微物理特征及人工增雨可播性研究

摘要

Based on the integrated analysis of the cloud data obtained by digital radar,and the particle measuring system made by DMT company,the main cloud physical parameters used to identify cloud seedability are proposed.The vertical distribution of cloud supercooled water content from 0℃layer height （1500 m） is calculated as follows：the cloud water content has a maximum of 0.416 g·m^-3 at 400 m height above the 0℃layer,then as the distance from the 0℃layer height increases,the supercooled water content in clouds decreases,rapidly reaches to the lowest at the 600 m height above the 0℃layer,from this height to the cloud top,the cloud maintains low water content.Only when the relevant cloud particle concentration obtained by CDP probe of DMT is larger than 30 cm^-3,would the cloud area have certain seedability.Furthermore,when the particle concentration obtained by CIP probe of DMT is less than 10 cm^-3,the cloud would be highly seedable and otherwise it is generally seedable.%利用DMT探测平台对2009年3月11日山西云降水观测外场试验区的一次云降水过程实施了综合探测,综合分析了此次云降水过程的宏微观物理特征。计算了云中过冷水含量距0℃层高度（1500m）的垂直分布：云中过冷水含量最大值出现在0℃层高度以上400 m处,其最大值为0.416 g·m^-3,之后随着距0℃层高度的增加,云中过冷水含量迅速减小,到0℃层高度以上600 m处基本为最低,之后直到云顶,云中过冷水含量维持低值。CDP探头探测的云中粒子浓度以及CIP探头探测的云中大粒子浓度应作为判别云中可播度的两项主要指标,CDP探测的粒子浓度不小于30个·cm^-3的云区才具有一定的可播度,其中CIP探测的大粒子浓度小于10个·cm^-3时,可确定为强可播区。云滴浓度随高度变化呈多峰分布,云中粒子谱型主要为双峰或多峰型。此探测过程中典型区域的粒子谱中均出现第二峰值的区段,分析表明只有当云粒子浓度不小于30个·cm^-3时,相应云区才具有一定的可播度。