成冰剂和吸湿性催化剂机载催化的气溶胶和CCN飞机观测试验分析

Aircraft Measurements of Aerosol and CCN for Airborne Glaciogenic and Hygroscopic Seeding Agents for Cold and Warm Cloud Seeding

为研究目前人工影响天气广泛使用的两类催化剂(成冰剂和吸湿性催化剂)在自然大气中燃烧后对气溶胶的影响,及其初生粒子的核化特性,利用搭载气溶胶和云凝结核(CCN)观测设备的增雨飞机设计开展了一次晴空成冰剂、吸湿性催化剂燃烧的尝试性观测试验。结果发现,机载探测设备由于观测尺度范围受限未能检测到成冰剂燃烧前后气溶胶和CCN的微物理变化;吸湿性催化剂燃烧后,观测到气溶胶和CCN(0.3%过饱和度)粒子数浓度明显增加,分别达到1772.4 cm^(-3)和1809.01 cm^(-3),是燃烧前的4倍以上,粒子谱峰值是燃烧前的4.8倍;播撒产生的气溶胶粒子尺度范围在0.5μm以下,峰值直径从播撒前的0.17 m减小到播撒后的0.14 m。文章基于观测事实对焰条催化燃烧后成核率以及新型催化方式进行了探讨,试验方法可为更深入研究催化剂以及各种复合燃剂燃烧后产生粒子的物理和化学特性提供参考,研究成果可为云催化模式特别是暖云催化模型的建立提供客观的初始场数据支持。

In order to study the influence of two kinds of cloud seeding agents,glaciogenic agents and hygroscopic agents,which are widely used in weather modification,on microphysical characteristics of aerosol particles produced by combustion in natural atmosphere,an experimental study on the combustion of seeding agents for cold and warm cloud seeding in clear sky was carried out based on a weather modification aircraft equipped with aerosol and cloud condensation nuclei(CCN)observation equipment.The results show that the airborne detection equipment could not get the microphysical changes of aerosol particles and CCN before and after the combustion of glaciogenic agent due to the limited observation scale of the aerosol equipment.However,after the combustion of hygroscopic agents,we found that the aerosol and CCN particle number concentrations increased significantly,reaching 1772.4 cm^(-3)and 1809.01 cm^(-3)respectively,which were more than 4 times of those values before the hygroscopic agents combustion.Most of the aerosol particles’sizes were below 0.5μm with peak diameters decreasing from 0.17μm before seeding to 0.14μm after seeding,and the peak value of particle spectrum was 4.8 times of that before combustion,so it had the significant characteristics of forming CCN.Based on the observation results,the nucleation rate after flame catalytic combustion and the new catalytic ways are discussed.The method used in this aircraft experiment could provide scientific references for further studying the physical and chemical characteristics of the particles generated by combustion of cloud seeding agents.Furthermore,the research results could provide objective initial field data support for the establishment of cloud catalytic models,especially for warm cloud catalytic models.