Origin, transport, and vertical distribution of atmospheric pollutants over the northern South China Sea during the 7-SEAS/Dongsha Experiment

► First detailed aerosol optical properties in northern South China Sea were investigated. ► Back-trajectory analysis suggested 52% continental origin and 48% oceanic origin. ► Continental origin, mainly from Chinese coastal areas, with higher aerosol loading. ► Comparison with inland measurements, aerosol evolution and mixture were addressed. ► Upper-level (3-4 km) transport of biomass-burning aerosol was investigated by lidar.