| Abstrakt: |
To investigate the spatial changes in origins and impact of long‐range transported air masses on organic aerosols (OA) loading and composition over Northeast Asia, fine aerosols (PM2.5) were collected at three sites: Tianjin (TJ), North China and in Padori (PD), and Daejeon (DJ), South Korea, during winter 2019. We studied molecular distributions and compound‐specific stable carbon isotopic composition (δ13C) of dicarboxylic acids, oxocarboxylic acids and α‐dicarbonyls, and carbonaceous and inorganic ionic components in PM2.5. Concentrations of organic carbon was drastically enhanced in haze period compared to that in clean period, but elemental carbon was almost comparable between the two periods. Concentrations of total diacids, oxoacids, and α‐dicarbonyls were higher at TJ followed by DJ and PD during haze period and at DJ followed by TJ and PD during clean period. On average, oxalic acid (C2) was the most abundant among measured species at all three sites, followed by methyl glyoxal (MeGly) and glyoxylic acid (ωC2) at TJ and DJ, and succinic acid (C4) and ωC2were almost equal and second most abundant followed by MeGly at PD. Based on the mass ratios and linear relations of selected species together with δ13C of diacids and related compounds, we found that contributions of OA from biomass burning/biogenic emissions and their aging were higher at TJ and PD, whereas at DJ, emissions from anthropogenic sources and in situ secondary formation were also important. Furthermore, this study implies that long‐range atmospheric transport of aerosols from source regions to downwind regions are substantial over Northeast Asia. Fine atmospheric aerosols (PM2.5) collected at three sites: Tianjin (TJ), North China and in Padori (PD), and Daejeon (DJ), South Korea, during winter 2019 were studied for molecular distributions and compound‐specific carbon isotopic composition (δ13C) of dicarboxylic acids (diacids), oxocarboxylic acids (oxoacids), and α‐dicarbonyls as well as the carbonaceous and inorganic ionic components. The results obtained from this study suggested that the contributions of organic aerosols from biomass burning/biogenic emissions and their photochemical secondary formation and transformations (aging) are higher at TJ and PD, whereas at DJ, the emissions from anthropogenic sources and in situ secondary formation are also important. This study also implies that contributions of long‐range transported aerosols from source regions to downwind regions such as PD and DJ are substantial over Northeast Asia. Diacids, oxoacids, and α‐diacarbonyls were characterized in fine aerosols (PM2.5) from Tianjin, China, and Padori and Daejeon, South KoreaBiomass burning/biogenic emissions and their aging are higher at Tianjin and Padori and anthropogenic emissions are also important at DaejeonLong‐range atmospheric transport of the air masses from source regions to downwind regions are substantial over the Notheast Asian region Diacids, oxoacids, and α‐diacarbonyls were characterized in fine aerosols (PM2.5) from Tianjin, China, and Padori and Daejeon, South Korea Biomass burning/biogenic emissions and their aging are higher at Tianjin and Padori and anthropogenic emissions are also important at Daejeon Long‐range atmospheric transport of the air masses from source regions to downwind regions are substantial over the Notheast Asian region |
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