Abstract. Understanding the lifecycle of light-absorbing carbonaceous aerosols, from emission to deposition, is critical for assessing their climate impact. This study integrated multi-year aerosol observations from the ATOLL (Lille metropolis, northern France) platform, with air mass back-trajectories and emission inventory as a newly developed ‘INTERPLAY’ approach. Applied to Black Carbon (BC), the method apportioned source contributions (shipping, vehicular, residential heating, industrial) and studied aerosol aging effects, notably on the Brown Carbon (BrC) component. Results estimate that throughout the year, vehicular traffic dominated BC (31 %), followed by shipping (25 %, of which one-third was from canals/rivers) and residential heating (21 %). Comparing INTERPLAY results with the aethalometer model highlights that the ‘residential sector’ BC can be entirely apportioned to BC from wood burning (BCwb), notably in winter, while vehicular traffic corresponds to only about 41 % of BC fossil fuel (BCff) at the ATOLL site, the rest being apportioned to shipping (33 %) and industrial (23 %) emissions. Thus, vehicular traffic and BCff should not be used interchangeably, particularly in regions near intense maritime traffic. Concerning BrC, our analysis confirms a dominant role of residential heating. Focusing on winter, results suggest a considerable decrease in the BrC component only 24 hours after emission, with fresh residential emissions being responsible for 72 % of BrC absorption at ATOLL. Improving our understanding of sources and dynamics of light-absorbing carbonaceous aerosols is crucial for both source abatement strategies as well as a better assessment of their climate impact.