河北省降水性层状云宏微观物理特征

摘要

Based on the observational data from the 17 flights and the corresponding detecting data from the airborne new-generation particle measuring system (PMS) in spring and autumn of 2009 in Hebei province,the microphysical characters of precipitable stratiform cloud were analyzed.The results indicate that the precipitable stratiform cloud is mainly the multi-layer cloud system including nimbostratus (Ns) altostratus (As) and stratiform cloud (Sc) in Hebei province,and it often accompanies with layer-separating phenomena.The mean height of cloud base,the supercooled layer thickness and 0 ℃ layer height are 2002 m,1106 m and 3 811 m,respectively.For the microphysical characters,the mean number concentration and mean diameter of cloud droplet are 54.6 cm-3 and 8.64 μm and both are smaller than those in 1990s,while the liquid water content is 0.13 g·m-3 that is larger than that in 1990s.%利用2009年河北省春秋季17架次飞机宏观观测资料和相应的机载PMS云微物理探测数据,经过回放处理、筛选和计算,统计分析近年河北省降水性层状云物理特征.结果表明:河北省降水性层状云是以Ns、Sc、As为主的多层云系,且多伴随有干层结构.云底平均高度、过冷层厚度、0℃层高度分别为2002、1106 m和3811 m.微物理方面,云滴数浓度平均为54.6 cm-3,平均直径为8.64μm；云粒子浓度和尺度均比20世纪90年代各特征值有所减少.统计计算的降水性层状云中液态水含量为0.13 g·m-3,远大于20世纪90年代测值.