Preliminary Results of Cloud Seeding Experiments for Air Pollution Reduction in 2020

In previous studies, cloud seeding has been primarily used to increase precipitation; however, its use for the purpose of reducing particulate matter concentration has not yet been adequately addressed. In this study, we investigated the effect of cloud seeding on the reduction of fine dust concentration by conducting two airborne experiments in west Korea along the Yellow Sea coast on November 1, 2020. Numerical simulations showed that the seeding material diffused in Seoul, Gyeonggi-do, and Chungcheongnam-do as observed from the prevailing wind direction. We also observed enhanced radar reflectivity in these areas, and analysis of aircraft observation data revealed that the average concentration of cloud, drizzle, and precipitation particles increased after seeding as compared with the observations before and during seeding. Further, the precipitation particles had large diameters after seeding; particularly, PM₁₀ (particulate matter with size ≤ 10 µm) concentration tended to decrease owing to precipitation in the areas affected by cloud seeding; however, it remained unchanged in the unaffected areas. Although it is necessary to conduct further experiments to obtain more comprehensive results, the findings of this study highlight the possibility of reducing fine dust concentration in the atmosphere via cloud seeding.