Vertical Distributions of Refractory Black Carbon over the Yellow Sea during the Spring 2020

Black carbon (BC) is a light-absorbing particle that strongly absorbs visible light and called short-lived climate pollutant. In this study, refractory black carbon (rBC) was measured onboard the Gisang Aircraft using a single particle soot photometer (SP2) over the Yellow Sea during March 20~June 03, 2020. For the seven flights, the range of number and mass concentration of rBC and the number concentration of scattering particles were <10~320 cm^-3, <5~710 ng m^-3, and <10~2299 # cm^-3, respectively. In addition, the geometric mean mass diameter (D_gm) of rBC and thick-coated rBC fraction (F_thick-coat) were 167~182 nm and 34~58%, respectively. Generally, rBC number and mass concentration and the number concentration of scattering particles were higher at planetary boundary layer (PBL) than free troposphere (FT) and rBC concentration was particularly affected by the PBL development. As the PBL height increased, the concentrations of rBC and scattering particles decreased. It was found that the evolution of boundary layer affected the vertical distribution of rBC properties over the Yellow Sea.