Abstract: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 0.5 μm with peak diameters decreasing from 0.17 μm before seeding to 0.14 μm 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.