Overview of submicron aerosol characterization in China using an Aerodyne high-resolution aerosol mass spectrometer

China is one of the most rapidly developing countries in the world, but in the meantime it is suffering from severe air pollution due to heavy industrial/metropolitan emissions. Most previous aerosol studies in China were based on filter sampling followed by laboratory analysis, which provided datasets at a coarse time resolution like a day. The coarse time resolution of the aerosol datasets cannot match the actual faster variation of aerosol properties in the real atmosphere, which strongly favors highly time-resolved on-line measurement techniques. In recent years, our group deployed an Aerodyne high-resolution aerosol mass spectrometer (AMS) in different ambient atmospheres in China, including Beijing (urban), Shanghai (urban), Shenzhen (urban), Jiaxing (suburban), and Kaiping (rural). In this presentation, we will overview these on-line AMS measurement results to characterize the properties of submicron particles in China atmosphere, such as chemical composition, size distribution, diurnal variation, elemental composition, primary and secondary organic aerosol constitution, etc. The newly-developed AMS-PMF modeling techniques were utilized to quantitatively differentiate the contributions from fossil fuel combustion, cooking emissions, biomass burning, as well as secondary organic aerosol to ambient organic aerosol loadings in China. These AMS results have provided new outlook of the formation mechanisms of high aerosol pollution in China.