Abstract
Arctic amplification (AA) refers to the enhanced warming of the Arctic relative to the global mean, a phenomenon with far-reaching climatic and societal implications. While multiple drivers have been identified, the contribution of aerosol–cloud interactions (ACIs) remains poorly constrained. This study quantifies the role of ACIs in historical AA from 1980 to 2014 using a combination of satellite observations, reanalysis data, and climate model simulations. We employ a novel radiative kernel approach to isolate the direct and indirect radiative effects of aerosols on Arctic clouds, and we assess their impact on surface temperature trends. Our results show that ACIs contribute 0.25 ± 0.08°C decade⁻¹ to the observed Arctic warming, accounting for approximately 18% of the total AA over the study period. The dominant mechanism is the cloud lifetime effect, which enhances longwave cloud radiative forcing in the cold season. Sensitivity experiments using the Community Earth System Model (CESM) reveal that anthropogenic aerosol emissions from mid-latitudes are the primary source of Arctic ACI forcing. Our findings underscore the importance of representing ACIs accurately in climate models to improve projections of future Arctic change and highlight the need for regionally targeted aerosol mitigation policies.