Rapid dark aging of biomass burning as an overlooked source of oxidized organic aerosol
John K. Kodros, Dimitrios K. Papanastasiou, Marco Paglione, Mauro Masiol, Stefania Squizzato, Kalliopi Florou, Ksakousti Skyllakou, Christos Kaltsonoudis, Athanasios Nenes, Spyros Ν. Pandis
Abstract
radical) rapidly form OOA in the laboratory over a few hours and without any sunlight. The extent of oxidation is sensitive to relative humidity. The resulting OOA chemical composition is consistent with the observed OOA in field studies in major urban areas. Additionally, this dark chemical processing leads to significant enhancements in secondary nitrate aerosol, of which 50 to 60% is estimated to be organic. Simulations that include this understanding of dark chemical processing show that over 70% of organic aerosol from biomass burning is substantially influenced by dark oxidation. This rapid and extensive dark oxidation elevates the importance of nocturnal chemistry and biomass burning as a global source of OOA.