Wintertime Aerosol Characteristics over Seoul and Their Impact on Suspended Solids in the Han River

Aerosols play a crucial role in atmospheric processes, influencing cloud dynamics, precipitation, and water resource management. In December 2016, an airborne observational campaign was conducted over Seoul to characterize the vertical distribution of background atmospheric aerosols using a multi-level leg flight strategy along the Han River. This study also analyzed suspended solids (SS) concentrations in the Han River to examine their relationship with aerosol distributions. Observations revealed a consistent decrease in aerosol concentrations with increasing altitude, along with distinct differences in aerosol characteristics observed within and above the planetary boundary layer (PBL). Urban areas exhibited higher aerosol concentrations compared to suburban regions, particularly for small particles (D<0.6 μm), suggesting that urban environments are the primary sources of these aerosols. Additionally, aerosol concentrations showed an increasing trend from the upper to the lower reaches of the Han River. Similarly, SS concentrations exhibited a downstream increasing pattern, demonstrating a comparable variation trend between SS concentrations in the river and aerosol concentrations in the atmosphere. These findings indicate a potential link between atmospheric aerosol distributions and water quality dynamics. This study presents the first dataset on vertical aerosol profiles over central Seoul, providing valuable insights for validating satellite and lidar observations. The results also offer implications for developing cloud-seeding strategies and enhancing water resource management under changing climate conditions. By highlighting the interconnectedness of atmospheric and water systems, this study underscores the critical need for integrated aerosol and water quality monitoring to address complex environmental challenges in urban and watershed systems.