不同冰核核化过程对雷暴云微物理过程和降水的影响

Impact on Precipitation and Microphysical Process in Thunder Cloud under Different Ice Nucleation Process

基于已有的二维对流云模式,加入一种新冰晶核化参数化方案;并通过对不同冰晶核化方式进行模拟对比,探讨不同冰晶核化过程对云内微物理过程及降水的影响。结果表明:考虑气溶胶异质核化作用以及均质冻结核化与异质核化的竞争关系后,地面降雨明显延后,地面累积降雨量减弱,降雨整体受到抑制。通过对微物理过程分析发现,主要有两个成因。异质核化过程的加入,导致冰晶特别是在高温区快速增长,加剧了云水以及水蒸气的消耗,致使云水碰并效率降低,抑制了雨滴的碰并增长;云滴和雨滴含量的减小减弱了其与霰粒子的碰并效率,霰粒子增长变缓,下落末速度降低,霰融化过程明显滞后。

Based on the existing two-dimensional model of convective clouds,a new ice nuclei parameterization was added to study the effect of the ice nucleation on the cloud microphysical process and precipitation. The result indicates that the ground rainfall was significantly delayed,and the cumulative rainfall and total rainfall were inhibited,when considering aerosol heterogeneous effect and its competition between homogeneous freezing nucleation. In addition,by adding the heterogeneous nucleation process in the microphysical process,found that ice crystals especially in high temperature region were increased significantly,the consumption of cloud water and water vapor were intensified,the collection efficiency of cloud water was weakened,and the coalescence growth of raindrops was inhibited. Moreover,when cloud drop and rain drop＇s content were decreased,their collision with graupel was weakened,and the growth,falling speed and melting speed of gaupel were inhibited.