摘要
对2004年6月12日甘肃河西地区一次降水性层状云的云物理飞机探测结果进行了分析,通过对云中粒子的浓度、直径、二维图像以及谱型变化地研究,并结合宏观观测记录,详细分析了云系的垂直和水平微物理特征。观测资料分析表明:此次云系为Ac-Sc结构,上层Ac云为纯冷云,下层Sc云为纯暖云,两层云之间存在较厚的干层。云中微物理量的垂直和水平变化均具有明显的不均匀性,整个探测过程中,FSSP-100所测云粒子的浓度和平均直径变化范围分别为0.1～232.6cm^(-3)和3.5～45.5μm,OAP-2D-GA2所测云粒子浓度及平均直径变化范围分别为0.01～116.7 cm^(-3)和32.2～995.7μm。粒子二维图像表明,上层高积云中冰相粒子的凇附、粘连现象普遍,说明云中存在较多的过冷水。图像及谱型分析表明,6000m以上某些区域有冰晶高浓度区存在,大量冰晶的成长消耗了云中过冷水,不利于大云粒子的形成和成长;这次降水雨滴主要由纯暖性Sc云中暖云成雨过程形成,冷云过程只在Sc云顶附近有一定作用,本次降水主要机制为下层层积云中的暖云过程。
The cloud microphysical data measured by the airborne PMS probes in a precipitating stratiform cloud on June 12, 2004 in Hexi Corridor region of Gansu Province are analyzed. The cloud microphysical characteristics in both horizontal and vertical direction are presented through analyzing number concentration, mean diameter, shape and size distribution of cloud particles sampled with FSSP-100 probe and OAP-2D-GA2 probe. The results show that the cloud is Ac-Sc configuration, and dry layer between Ac and Sc clouds is deep. Both vertical and horizontal varieties of cloud microphysical parameter show obviously inhomogeneous features. The cloud particle number concentration measured by FSSP-100 changes from 0. 1cm^-3 to 232.6cm^-3, and the mean diameter is around 3.5- 45.5μm. The change scopes of corresponding data explored with OAP-2D-GA2 are respectively 0.01 -- 1167L- 1 and 32.2--995.7μm. The particle images indicate that the riming, accretion and aggregation of ice and snow crystals are quiet universal, and it shows that the super-cooled water content in cloud is high. There are high concentration regions above 6000m altitude. Growth of massive ice crystals consumes largely the super-cooled water, sequentially restraining the production or growth of big particles. The cool cloud processes are dominant during precipitation, and warm cloud processes is not distinct in Sc cloud.
出处
《气象》
CSCD
北大核心
2009年第1期24-36,共13页
Meteorological Monthly
基金
国家科技支撑计划重点项目(2006BAC12B04)专题
关键词
微物理
飞机探测
层状云
microphysics aircraft observation stratiform cloud
