Abstract:

Based on the airborne observation data obtained by the Particle Measuring System (PMS) over the central region of Hebei on April 4, 2013, the microphysical characteristics and artificial precipitation conditions of the stratus cloud were analyzed by combining with Micaps, satellite and additional precipitation observation, etc. The results show that the seeding cloud was a typical precipitation stratus. The average number concentration of small cloud droplet was 147 cm^-3 in the seeding cloud, and the maximum concentration was 737 cm^-3, the mean diameter of cloud droplet was 4.29 μm. The mean value and the maximum value of super cooled liquid water content in cloud was 0.03 g/m³ and 0.51 g/m³, respectively. The maximum number concentrition of ice crystals was 1.12×10^-3个/(cm³·μm) in the distribution of cloud droplet spectrums and it was quite suitable to be seeded. The seeding effect was significant by calculating the rainfall variation rate in the seeding zone and the contrast zones. The quantitative calculations show that the rainfall significantly increased in 3-4 hours after seeding operation and the rainfall amount in the seeding region was 1 to 3 times more than that in the contrast region. Comprehensive analysis confirmed the effectiveness of the seeding operation. The radar reflectivity was more related to surface rainfall than TBB.

Key words: stratus, microphysical characteristics, cloud seeding effect, Particle Measuring System (PMS)

摘要：

利用2013年4月4日河北中部地区一次针对降水性层状云系催化作业的飞机探测资料，结合气象信息综合分析处理系统（简称Micaps）、卫星和加密雨量等观测资料，对该层状云的微物理特征及人工增雨作业条件进行了综合分析。结果表明，此次过程为典型降水性层状云，作业层中小云粒子平均浓度为147个/cm³，最大浓度为737个/cm³，平均直径4.29 μm。云中含水量平均值为0.03 g·m^-3，最大值为0.51 g·m^-3，冰晶谱浓度最大值为1.12×10^-3个/(cm³·μm)，适合播撒作业。作业影响区和对比区雨量变化表明，作业后3~4 h影响区雨量增加最为显著，为对比区雨量的1~3倍，可以认为作业有一定效果。此外，作业区和对比区的雨量比值和雷达反射率相关性远高于云黑体亮温。

关键词: 层状云, 微物理特征, 催化效果, 粒子测量系统（PMS）