人工防雹实用催化方法数值研究

Numerical Studies of the Practical Seeding Methods in Hail Suppression

目前 ,我国普遍采用高炮和火箭两种催化工具进行人工防雹 ,但就如何提高这两种作业工具的有效性还缺乏系统的研究。作者利用三维冰雹云数值催化模式 ,选取 1 999年 7月 1 8日陕西省旬邑地区的冰雹云作为试验个例 ,分别就高炮催化不同的作业时间、催化剂量、作业部位、催化方式等 ,以及对火箭催化所携带的高效AgI焰剂的成核率与火箭在作业过程中以不同的发射距离、发射仰角和当火箭方位角发生偏离后对地面防雹效果的影响进行数值模拟 ,以期为提高防雹效果提供一些技术参考。

Seeding tools of AgI-containing artillery shells and rockets are widely used in hail suppression at present. But systematic studies on their efficiencies are lacking. In this paper, a hailstorm occurred in Xunyi area of Shaanxi province on July 18, 1999 is detailedly simulated by using the three-dimensional hail cloud numerical model introduced (by IAP.CAS). First, the influences of varied seeding times, seeding amounts, seeding positions and seeding methods with flak shells on hail suppression are given. Second, we test the seeding efficiency with one kind of AgI pyrotechnics which generates a much higher nucleation rate. At last, detailed simulations of the same hail cloud seeded with a rocket which is fired at different distances, different elevations, and also at different azimuths when they deviate within 5 or 10 degrees are analyzed. From those results obtained above, we expect to get some guidances to the improvement of the seeding efficiencies in practice.