【作者】 崔雅琴；

【导师】 王振会； 肖辉；

【作者基本信息】 南京信息工程大学 ， 大气物理学与大气环境， 2006， 硕士

【摘要】 近年来中国科学院大气物理研究所已建立和发展了一个具有人工影响天气催化模拟功能的三维对流云数值模式(简称IAP-CSM3D)。为了更合理地模拟人工催化冰晶的作用,本文对该模式中催化部分的人工冰晶参数化方案进行了改进,将人工冰晶和自然冰晶作为两种不同的冰晶分开来处理,把人工冰晶作为单独预报量,并考虑播撒粒子是按一定谱型分布的。假定人工播撒粒子的谱型与自然冰晶谱型相似,为双参数粒子谱,推导出人工冰晶与其它水成物粒子之间发生相互作用的微物理过程参数化方程,列出有关微物理过程的源汇项,给出人工冰晶比含水量和比数浓度的预报方程。并对Grads作图界面进行相应的修改,使改进后的三维对流云模式所模拟的微物理过程可以直观的通过图形界面显示出来。 利用改进后的三维对流云数值模式,详细模拟了2005年7月8日发生在辽宁省朝阳市的一次冰雹云天气过程,模拟的自然云与实际观测较为吻合。进而进行了不同剂量、不同播撒时间的AgI催化剂播撒试验,结果表明,当催化剂量由少到多增加时,降雹量越来越少,但当催化剂量增加到一定的值时,降雹量不再继续减少,因此,催化剂的用量并不是越多越好。使用相同剂量的催化剂在不同时间进行播撒,发现随着催化时间后移,降雨量是增大的,而降雹量是先减少后增加。使用改进前和改进后的模式分别进行催化试验,改进前后的模式都取得了较好的催化效果,但是在催化部位、时间、剂量相同的情况下,改进后模式的消雹效果要比原模式好。本文还分析了人工冰晶的微物理过程。 另外,本文使用改进后的三维流云数值模式模拟了发生于3个不同地区的强对流风暴个例,发现冰雹的产生与强上升气流区有较好的对应关系,模拟自然云雷达回波能比较好的显示出强对流风暴的特征,并总结出较好的催化时机。更多还原

【Abstract】 On the base of the IAP Three-Dimensional Convective Storm Model (IAP-CSM3D), its parameterization of cold-cloud seeding function was improved. Natural ice crystals and artificial ice crystals were entirely detached. In the ameliorated model, artificial ice crystals by cloud seeding were treated as a separate predictand. The spectrum of artificial ice crystal was considered as double-moment parameterization to more accord with fact. And parameterization equations of microphysical processes that contact with artificial ice crystals were also deduced.The interface of Grads was also changed to intuitionistically display the microphysical processes of convetive cloud simulated by the improved IAP-CSM3D.Then a hailstorm event occurred at Chaoyang City on July 8, 2005, was simulated by the improved IAP-CSM3D. The simulated cloud was in accord with the observation. A series of Agl-seeding experiments of the cloud were carried out by different seeding amount and different seeding time. The results show that the more AgI used, the little hailfall is. But when the amount of AgI is too more, the amount of hailfall will become increasing. So the amount of AgI is not too more too better. When the same dosage of AgI seeding was used at different time, the simulated results show that the later seeded the more rainwater get down and the hailstone is reduced in the early but increased in the latter. The improved IAP-CSM3D is better than the older in the effect of reducing hailstone.In addition, three strong convective storm events were simulated by the improved IAP-CSM3D. The results show that the hailstone-producing area has a good relation with fierce updraft. The characters of strong hailstorm were better showed on the simulated natural cloud radar echo. Suitable seeding time is also summarized.更多还原