Characteristics of Carbonaceous and Organic Components in PM2.5 over the Yellow Sea

Characteristics of carbonaceous components and organic compounds in PM2.5 over the atmosphere of the Yellow Sea were investigated. PM2.5 samples were collected onboard the meteorological research vessel, GISANG 1, over the Yellow Sea during the YES-AQ campaign in 2018 and 2019, respectively. The average concentrations of carbonaceous components in this region were 2.59 +/- 1.59.g m(-3) for the OC, 0.24 +/- 0.10.g m(-3) for the EC, 2.14 +/- 1.30.g m(-3) for the WSOC and 1.17 +/- 0.94.g m(-3) for the HULIS-C, respectively. The total concentration of 56 organic compounds (Sigma OCs) accounts for 10% of OC. The main group among organic compounds were dicarboxylic acids which account for 57% of Sigma OCs, followed by n-alkanoic acids accounting for 34% of Sigma OCs. In n-alkanoic acid distribution, hexanoic (C-6:0) and octanoic (C-8:0) acids which are low molecular weight n-alkanoic acids and known as emitted from marine biogenic activities were dominant in this region. Furthermore, non-HULIS-C fraction increased when the air mass originated from the marine region rather than the continental region. When the Asian dust episode was observed, the WISOC concentrations along with the levoglucosan were increased, while the haze episodes caused the increase of WSOC, HULIC-S and DCAs. In this study, we found that the components of carbonaceous and organic aerosols in PM2.5 over the Yellow Sea were changed with the specific air pollution episodes. It indicates that the physicochemical properties of PM2.5 can be changed by the air pollution episodes in this region.