Retrieval of PM_2.5 aerosol mass concentration in the Arctic region

Arctic aerosol pollution exerts profound impacts on regional climate and environmental systems; however, its quantification remains challenging due to the scarcity of ground-based monitoring stations in this harsh environment. To address this gap, we developed a novel PM_2.5 retrieval algorithm specifically tailored for the Arctic region (60°-82°N). By synergistically integrating AERONET sun photometer data, CALIPSO satellite active remote sensing, and ground measurements (2007-2020), the method demonstrates strong agreement with in situ observations. Furthermore, we characterized seven distinct Arctic aerosol types using multi-platform observations. These analyses reveal unique particle size distributions: fine-mode dominated aerosols exhibiting unimodal (clean marine, dusty marine, elevated smoke), bimodal (clean continental, polluted continental/smoke, polluted dust), and trimodal (pure dust) structures, with peak radii spanning 0.11-5 μm. These findings advance the understanding of Arctic aerosol microphysical properties and establish a robust tool for monitoring pollution in this climate-sensitive region.