Monitoring Atmospheric Aerosol Pollution in Kyiv in 2024 under Natural and War-Related Impacts using Sentinel-5P and Public Sensor Networks

This study presents a comprehensive spatiotemporal assessment of aerosol air pollution in Kyiv during 2024, integrating data from ground-based public monitoring stations and Sentinel-5P satellite observations. The focus was on PM2.5 and PM10 particle concentrations and their relationship with the Absorbing Aerosol Index (AAI), particularly in the context of both typical urban emissions and additional pollution episodes caused by wartime activities such as missile strikes, explosions, and fires. Aerosol air pollution data were collected from seven SaveEcoBot stations in Kyiv. Hourly measurements were aggregated into daily and monthly averages. The annual mean concentrations were 14.64 ± 9.05 μg/m³ for PM2.5 and 23.06 ± 14.85 μg/m³ for PM10, generally remaining within EU air quality limits. Nevertheless, several peak exceedances were observed, particularly in spring (March) and autumn (September). Satellite-derived AAI values over Kyiv in 2024 averaged –0.44 ± 0.51. Seasonal dynamics revealed the lowest (most negative) AAI values during summer, while higher (less negative) values occurred in late autumn and winter-indicating increased loads of UV-absorbing aerosols likely associated with combustion products. Statistically significant correlations were found between monthly AAI and ground-based concentrations of PM2.5 and PM10, supporting the complementary use of satellite data for assessing air pollution trends. Despite daily-scale discrepancies due to differences in measurement altitude and emission origin, the combined data revealed spatial pollution hotspots in densely built-up areas with high traffic and limited greenery. The findings emphasize the importance of integrating remote sensing and ground-based approaches for monitoring urban air quality under conditions of environmental and military stress.