华北春季降水性层状云中冰相粒子形状分布  

Ice particle habit distribution in stratiform clouds at different precipitation stages

作　　者：黄敏松[1] 雷恒池[1] HUANG Minsong;LEI Hengchi(Key Laboratory of Cloud-Precipitation Physics and Severe Storms,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴重点实验室,北京100029

出　　处：《大气科学学报》2022年第2期247-256,共10页Transactions of Atmospheric Sciences

基　　金：国家重点研发计划项目(2018YFC1507900);国家自然科学基金资助项目(41775166;41705142)。

摘　　要：为了获取华北春季降水性层状云中冰相粒子形状分布及其在降水发展中的变化,利用机载云粒子成像仪(OAP-CIP)在三次层状云降水天气过程中所测粒子图像资料,分析了不同降水阶段不同温度区间内不同粒径范围下的冰相粒子形状分布特征,并研究了影响云中冰相粒子增长变化的关键微物理过程。结果表明:在降水发展早期,云中冰相粒子形状分布以霰和线形状为主,在500μm以上粒径统计中,这两者的出现频率分别在20%和40%以上;聚合状粒子除了在0~-4℃的温度区间内出现频率在10%~20%之间,其他温度区间内出现频率均在10%以下;云中粒子增长以凝华和凇附过程为主。在降水成熟阶段,霰和聚合状粒子是两种主要粒子形状,其出现频率在25%以上;线形状粒子在0~-4℃和-4~8℃温度区间内出现频率在10%~20%;板状粒子的出现频率在5%~15%;不规则状粒子在125μm粒径以上的粒子数统计中出现频率在10%以上,但其他粒径段则在10%以内且随统计粒径增大,其出现频率降低;云中粒子增长在凝华基础上以凇附和碰并聚合为主。To obtain the distribution features of ice particle habits in the precipitation stratiform clouds of northern China,the ice particle image data recorded by the airborne cloud particle imager(OAP-CIP)in three stratiform precipitation events occurring during the11th Five-Year National Key Technology Research and Development Program“Beijing Cloud Experiment(BCE)”were used to analyze the distribution characteristics of ice particle habits in different precipitation stages,along with temperature and diameter ranges.The following results were obtained:in the early stage of precipitation development,the habit distribution of ice crystal particles in clouds is dominated by graupel and line shape,and their respective occurrence frequencies exceed20% and40% with particle size of larger than500 μm.The occurrence frequency of aggregate in the temperature area of0to-4℃ ranges between10% and20%;however,it is quite low in other temperature intervals,at less than10%.The key microphysical processes affecting ice particles’ growth in the early stage are sublimation and riming.In the mature stage of precipitation,graupel and aggregate particles are the two main particle habits,and the occurrence frequencies of both greater than25%.The occurrence frequencies of linear particles at the temperature intervals of0to-4℃ and-4to-8℃ are both between10% and20%.The occurrence frequency of hexagonal particles is between5% and15%.The occurrence frequency of irregular is greater than10% at the size of larger than125 μm,but less than10% at other diameter size intervals,and decreases with the increase of statistical particle size.The key processes affecting the ice particles’ growth in this stage are riming and coalescence.

关 键 词：降水性层状云 冰相粒子形状 云微物理过程 飞机观测 

分 类 号：P426.6[天文地球—大气科学及气象学]