山东冰雹形成机制及雹云催化技术模拟——个例研究  

A case study of hail formation mechanism and hail suppression technique in Shandong Province

作　　者：樊明月[1] 张佃国[1] 龚佃利[1] 封秋娟[2] 华杰[1] 王永政[1] 张洪生[1] 郭建[1] 

机构地区：[1]山东省人工影响天气办公室,山东济南250031 [2]山西省人工降雨防雹办公室,山西太原030032

出　　处：《大气科学学报》2013年第1期107-120,共14页Transactions of Atmospheric Sciences

基　　金：国家科技支撑计划课题(2006BAC12B02);山东省气象局重点课题(2009sdqxz16)

摘　　要：利用中国科学院大气物理研究所开发的三维全弹性冰雹云模式,对2006年7月5日山东境内一次以冰雹、雷雨大风为主的强对流过程进行模拟,分析了冰雹的形成机制。结果表明:79%左右的冰雹胚胎是霰,雹胚以霰为主,霰主要来自于冰雪晶与过冷雨水碰撞冻结以及雪的自动转换过程,霰形成后主要靠碰并过冷云水、雨水增长,而冰雹主要质量来源是霰的自动转化以及碰并过冷云水增长。人工催化试验表明:在强对流云中冰雹含量达到0.1g·m-3前1～4min进行催化,能有效抑制冰雹粒子的增长,在过冷水含量中心(5.5km)上方1.0～1.5km催化防雹效果较好,在其下方催化防雹效果较差;剂量越大防雹效果越好。AgI主要以凝华核的作用产生人工冰晶,冰晶凝华增长导致过冷云水含量降低。催化后雹胚特别是霰胚的数量增多,对过冷云水的竞争增强,其平均尺度、质量均减小,降低了雹胚向冰雹的转化率。冰雹碰并过冷云水增长也被减弱,导致冰雹总质量进一步减少。The mechanism of hail formation and hall suppression technique are studied using the three dimensional hailstorm numerical model with fully elastic primitive equations, which is established by Institute of Atmospheric Physics, Chinese Academy of Sciences. The data used here are taken from a severe convective process with hailstorm and thunderstorm accompanied by gale occurred in Shandong Province on 5 July 2006. Simulation results show that 79% hailstone embryos are graupel particles, which are the main hail embryos. The dominant formation mechanism of graupel is the collision freezing of ice crystals, snow flakes with supercooled rain water and the auto conversion of snow. Once formed, the accretion of cloud water and rain water becomes the dominant growth mechanism of graupel particles. And the main growth mechanism of hail particles is the auto conversion of graupel and the ac- cretion of supercooled cloud water. The results of seeding show that the growth of hall particles can be effectively inhibited if the seeding happens between one to four minutes before the hail content reaches 0.1 g·m^-3. And the seeding effect is better at 6. 5-7. 0 km heights than that at the other heights.Generally, the more AgI, the better seeding effect. Artificial ice crystals are produced with the sublimation nucleus AgI, and the sublimation growth of ice crystal results in decrease of the supercooled cloud water content. The number of hailstone embryos especially the graupel particles increases after seeding, and these numerous smaller hailstone embryos compete for the less available supercooled cloud water, so the average size and quality of hailstones decrease. The conversion rate of hailstone embryos to hailstones is reduced. The accretion of supercooled cloud water by hailstones decreases after seeding, resulting in decrease of the hail amount.

关 键 词：雹胚 催化防雹 AGI 数值模拟 

分 类 号：P458.121.2[天文地球—大气科学及气象学]