针对2008年10月24日四川盆地上空未形成降水的低层暖云,利用夏延ⅢA飞机搭载的PMS系列探头进行了探测试验,分析了云的微物理结构.分析结果表明:云体构成以小云滴为主,大云滴浓度较低,降水粒子很少.云中小云滴的液态含水量、数浓度、直径在水平方向上分布不均.小云滴的液态含水量和小云滴的体积平均直径正相关.相对云上部,云底有较少的小云滴、大云滴(小雨滴)和更加稀少的降水粒子.未能形成地面降水主要是由于云中液态含水量很少,云的厚度薄,云滴凝结增长困难,云雨滴碰并不活跃,发生碰并的路径较短、时间不长.%Based on the airborne observation data obtained by the Particle Measuring System (PMS) in Sichuan Province on 24 October 2008, the characteristics of the autumn low-level warm clouds without ground precipitation are discussed. The results show that: (1) The low-level warm clouds were composed mainly of small cloud droplets, and the number concentration of large cloud droplets was relatively low, and the precipitation particles in the clouds were very few. (2) The liquid water content, number concentration and diameter of small cloud droplets were inhomogeneous in horizontal direction. (3) There was a positive correlation between the liquid water content and the mean diameter of small cloud droplets. (4) Compared with the upper layer of the clouds, there were less small cloud droplets and large cloud droplets (small raindrops) and fewer large raindrops in the cloud base. (5) Because of the small cloud liquid water content, thin cloud thickness, difficult condensation growth of cloud droplets, inactive coalescence growth, and short path and time of collision growth, there was no precipitation reaching the ground.
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