河北省层状云降水系统微物理结构的飞机观测研究

Airborne Observation for Microphysical Structure of PrecipitationSystem of Stratiform Cloud in Hebei Provice

对4架次飞行个例的PMS资料进行综合分析, 发现河北省春季层状云降水系统存在不均匀性, 表现之一为较强降水云带。1991年5月25日的个例在飞机上升和下降过程中两次在 2000 m左右探测到较强的云内逆温, 逆温层顶下方存在云水含量的峰值。对 1992 年 6 月 20 日两次个例的冷云的冰晶尺度、冰水含量(IWC)、冰晶浓度和液水含量(LWC)的垂直分布进行了分析。对两次个例的云中可播性进行判别, 发现潜力区占云区的1/2左右, 有时存在大片强可播区。

Based on integrated analysis of the cloud data obtained by the particle measuring system(PMS)in 4 cases in Hebei Province, it is found that the stratiform clouds of precipitation in spring are inhomogeneous, in which there exist cloud bands of severe precipitation.The inversion is detected at twice about the height of 2000 m aircraft ascending and descending on 25 May 1991. There is a peak value of liquid water content(LWC) below the top of the inversion layer. The vertical distributions of the ice crystal size, ice water content(IWC), ice crystal concentration and LWC on 20 June 1992 are analysized. The seeding condition criteria and operation indexes in cold stratiform clouds presented by Tao Shuwang et al^(\) are used to judge the seedability in cloud of 2 cases. It is found that the seedable clouds are about 1/2 of total clouds, sometimes there are a large scale highly seedable clouds.