Measurement Report: Evolving Sources and Composition of Urban Submicron Aerosols in Dublin: Impacts of Emission Reductions and Transboundary Transport

Abstract. Home heating remains a main driver of winter air pollution across many European cities, yet long-term evaluations of pollution trends and mitigation responses remain limited. Here we present continuous measurements of chemically-speciated PM1 (particles with aerodynamic diameter < 1 μm) in Dublin, a temperate European city influenced by local residential heating and continental pollution, from 2016 to 2023 to assess pollution trends under solid fuel reduction efforts. Two typical pollution types were identified: intense short-lasting events (few hours, PM1>100 µg m-3) driven by heating emissions, and moderate long-lasting events (several days, PM1