山西春季一次层状冷云的微物理结构特征

利用2009年3月11日机载DMT（droplet measurement technology）粒子测量系统获取的山西层状云探测资料,结合天气、卫星、雷达等,分析了降水性冷云的宏微观结构特征.结果表明,降水云系由高层云和层积云组成,液态含水量变化范围为0 0.42 g/m3.CDP（cloud droplet probe;云粒子探头）和CIP（cloud imaging probe;云粒子图像探头）观测到的粒子数浓度偏大,CDP探测到最大粒子数浓度为451.93 cm-3,CIP探测到最大粒子数浓度为162.78 L-1.本次探测适宜的人工增雨作业温度区间为-11.4-7℃、-4.40℃.高层云上部以冰晶的核化和凝华增长为主;高层云的中下部为冰雪晶活跃增长层;通过凝华、碰并机制高层云降落的冰雪晶粒子在层积云进一步长大.层状云水平分布不均匀特性很明显.统计云滴谱谱型分布发现,双峰型、多峰型出现几率较高,指数型主要出现在层积云的中部和顶部,出现单峰型时LWC（liquid water concentration;液态水含量）小于0.03 g/m3或大于0.1 g/m3.

Microphysical characteristics of spring precipitation cold stratiform clouds in Shanxi Province

Based on the weather and data from meteorological satellites and radars, the macrophysical and microphysical characteristics of the stratiform cloud in Shanxi Province on 11 March 2009 were analyzed by using droplet measurement technology （DMT）.The results showed that precipitation clouds were composed of altostratus and stratocumulus. Content of liquid water ranged from 0 to 0. 42 g/m3. Particle concentrations observed by cloud droplet probe （CDP） and cloud imaging probe （CIP） were large, whose maximum values were 451.93 cm-3 and 162. 78 L-1 respectively.Suitable temperature ranges for seeding were from- 11.4 to-7 ℃ and from-4. 4 to 0 ℃ .The upper portion of altostratus was the nucleating and sublimation growth area.The mid and lower portions of altostratus was the active growth layer of ice crystals.Ice crystals from altostratus grew up by sublimation and coagulation in the stratocumulus.The spatial distribution of stratiform cloud microphysical parameters was uneven.The cloud drop-let spectra were mainly of two-peak and multi-peak distributions.In the middle and top portions of stratocumulus, the spectra were exponential.When liquid water concentration（LWC） was less than 0. 03 g/ m3 or larger than 0. 1 g/m3, the spectra were unimodal.