Laboratory Insights into the Diel Cycle of Optical and Chemical Transformations of Biomass Burning Brown Carbon Aerosols.

ABSTRACT: Transformations of biomass burning brown carbon aerosols (BB-BrC) over their diurnal lifecycle are currently not well studied. In this study, the aging of BB tar proxy aerosols processed by NO₃^• under dark conditions followed by the photochemical OH^• reaction and photolysis were investigated in tandem flow reactors. The results show that O₃ oxidation in the dark diminishes light absorption of wood tar aerosols, resulting in higher particle single-scattering albedo (SSA). NO₃^• reactions augment the mass absorption coefficient (MAC) of the aerosols by a factor of 2-3 by forming secondary chromophores, such as nitroaromatic compounds (NACs) and organonitrates. Subsequent OH^• oxidation and direct photolysis both decom

SUBMITTER: Li C 

PROVIDER: S-EPMC7547865 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature