CHARACTERIZATION OF CARBONACEOUS PROFILES OF TROPICAL URBAN PM2.5

Abstract

Organic aerosols (OAs) in Singapore, an urban receptor environment in the Maritime Continent, are affected by domestic and cross-border sources, with transboundary peat forest (PF) smoke as a major source. By coupling source apportionment with the elemental carbon (EC) tracer method, this work aims to better understand the impacts of local and transported sources on OAs in urban PM2.5 through quantifying primary and secondary OAs (POAs and SOAs) with features of associated sources and locational. As a predominant source of the OAs, impacts of transboundary PF smoke on urban PM2.5 are further investigated through characterizing eight carbonaceous fractions of organic carbon (OC) and EC. The chemical evolution of transported PF smoke is also examined by investigating aqueous phase photooxidation of a semi-volatile PF smoke tracer compound (guaiacol).