Constraining aerosol optical models using ground-based, collocated particle size and mass measurements in variable air mass regimes during the 7-SEAS/Dongsha experiment

► First time attempt of optical closure at Dongsha in a dynamic aerosol environment. ► Observed optical properties are reasonably tracked by an optical model. ► Peak aerosol events and transitions between key types are captured. ► More resolved aerosol physicochemical datasets are needed for full optical closure.