冰晶核化对雷暴云微物理过程和起电影响的数值模拟研究  

Numerical Simulation Research on the Effect of Ice Nucleation on Thundercloud Microphysical Process and Electrification

作　　者：谭涌波[1,2] 杨忆[1,2] 师正[1,2] 周博文[1,2] 张冬冬[1,2] 廖义慧 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044 [2]南京信息工程大学中国气象局气溶胶与云降水重点开放实验室,南京210044

出　　处：《大气科学》2015年第2期289-302,共14页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展计划(973计划)项目2014CB441403;国家自然科学基金项目41175003;41475006;江苏高校优势学科建设工程资助项目PAPD;江苏省普通高校研究生科研创新计划项目CXZZ13_0515

摘　　要：本文在已有的二维对流云模式中采用了一种与气溶胶有关的冰晶核化方案替代原有的冰晶核化经验公式,并选取个例,分别就两种方案进行了模拟对比试验。模拟结果表明:(1)新方案所得冰晶比含水量主要分布在-0.1^-7.6°C温区之间,高于原方案所得的-50.1^-24.2°C温区;在整个雷暴云的发展过程中新方案冰晶的分布高度、温度区间以及最大浓度值均大于原方案。(2)在新方案中,温度相对较高的过冷区产生大量冰晶,其争食云中水汽抑制了云滴、雨滴的增长。此外,与原方案相比,霰增长受雨滴大幅减小的影响进一步得到限制,导致生成的霰小于原方案,且空间分布具有较大区别。(3)两方案在雷暴云初期形成的电荷结构不同;在发展旺盛与消散阶段新方案中电荷空间分布区域和电荷量均大于原方案,此外,在不同时刻主正电荷区和主负电荷区的中心高度存在差异。本文对云微物理过程及起电的分析为后继探讨气溶胶与雷暴云起放电过程、电荷结构之间的相互关系提供了有利条件。Based on an existing two-dimensional convective cloud model, this work adopts a nucleation scheme associated with aerosols to replace the original ice crystal nucleation empirical formula, and conducts a simulation contrast test on the two schemes. Simulation results show that： （1） The mass of ice crystals in the new scheme is mainly distributed in the --50.1℃ to --7.6℃ temperature region, higher than the original scheme＇s temperature region of --50.1℃ to --24.2℃. Throughout the thundercloud development process in the new scheme, the distribution height, temperature region, and maximum concentration value of ice crystals are greater than in the original scheme. （2） The new scheme produces a large number of ice crystals at relatively high temperature that dodge the water vapor and inhibit the growth of cloud droplets and rain. In addition, compared with the original scheme, graupel growth is greatly affected by the impact of raindrops and is dramatically reduced. This leads to the graupel being smaller than in the original scheme and to differences in its spatial distribution. （3） For thunderclouds, the early charge structure of the two schemes is different. The charge distribution area and amount of charge in the new scheme are greater than in the original scheme. In addition, the center heights of the main positive and the main negative charges differ at different times. This analysis of cloud microphysical process reveals the conditions favorable for researching the relationship between the thundercloud electrification process and the aerosol charge structure.

关 键 词：冰晶 核化方案 微物理过程 云模式 

分 类 号：P446[天文地球—大气科学及气象学]