【作者】 史月琴； 楼小凤； 邓雪娇； 胡志晋； 周秀骥；

【Author】 SHI Yueqin1, 2, LOU Xiaofeng2, DENG Xuejiao3, HU Zhijin2, and ZHOU Xiuji2 1 Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871 2 Chinese Academy of Meteorological Sciences, Beijing 100081 3 Guangzhou Institute of Tropical and Marine Meteorology, Chinese Meteorological Administration, Guangzhou 510080

【机构】 北京大学物理学院大气科学系； 中国气象科学研究院； 中国气象局广州热带海洋气象研究所；

【摘要】 在对华南2004年3月31日～4月1日的冷锋降水天气过程进行正确模拟的基础上,通过向云中引入人工冰晶研究了催化效应,结果表明:催化使地面雨量在催化后30min开始增加,80min时达到峰值,120min时减小到最小值。被催化的云团随着自然雨带逐渐向东南方向移动,并且催化云影响其周围的云团,造成了催化的下风方域外效应,使催化效果可以延长到催化后10个小时,随着自然云的消散而结束。人工冰晶的引入,使得大量过冷雨滴快速转变为霰粒,霰粒通过淞附云水和碰并雨滴过程增长,使降水提前发展,之后霰粒的融化使地面雨量增加。大量冻结潜热的释放,使云中温度增加,上升速度增强,说明"静力催化作用"和"动力催化作用"是相互关联不可割裂的。在云体发展早期冷云降水过程还没有启动之前引入人工冰晶的催化效果优于云体发展接近成熟时的催化效果,而只由催化剂量的不同造成的增雨差异较小。更多还原

【Abstract】 Based on the reasonable simulation of cold frontal precipitation event in South China on 31 March 2004, seeding effects through directly adding ice crystals in the simulated clouds are studied. The results show that after seeding 30 minutes surface rainfall started to increase, after seeding 80 minutes the Net Rainfall Increment (NRI) reached a peak, then after 120 minutes NRI decreased to a minimum. The seeded cloud moved southeasterly with the natural precipitating band moving, and the seeded cloud influenced the neighboring clouds, which caused the seeding effects last about 10 hours, then dissipated with the natural clouds dissipating. The seeding effects conformed to the hypothesis of "downwind extra-area effects". Supercooled raindrops were quickly transferred into graupels after artificial ice crystals were injected. Then graupels grew mainly through riming supercooled cloud water and collecting raindrops. Thus precipitation developed in advance, then the melting of graupels caused the surface rainfall increase. The release of a large quantity of fusion latent heat made the temperature in cloud increase, strengthened the updrafts, which indicated that "static seeding" and "dynamic seeding" are correlative each other. The seeding effects of adding ice crystals in the cloud developing stage were better than those in the cloud mature stage. The difference of NRI caused only by the seeding agent dose in different seeding experiments was relatively small.更多还原