Sources of organic aerosols in east China: A modeling study with high-resolution intermediate-volatility and semi-volatile organic compound emissions

Organic aerosol (OA) contributes a large fraction of atmospheric submicron aerosol and has negative impacts on air quality, climate, and human health. Sources of OA still remains unclear due to the inadequacy of emission inventory and modeling system. Herein, we established a high-resolution emission inventory of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) and applied it into CMAQ to simulate POA and SOA from different sources in eastern China. Comprehensive observation data of organic carbon (OC), primary and secondary organic aerosol (POA, SOA), and precursors were used for the verification of model performance. With the addition of I/SVOC emissions, OA simulations in each season were substantially improved by increasing the modeled SOA by 1.2 times. I/SVOC emissions contributed 53.6% of SOA and 23.5% of total OA on average. Cooking emissions dominated the POA concentrations in most of the cities. I/SVOC emissions from industrial sources have become the predominant source of regional SOA, followed by those from mobile sources. The differences in OA source contributions between the cities implies that differentiated control measures shall be considered to OA pollution mitigation. Meanwhile, more localized I/SVOCs emission measurements and more sophisticated SOA simulation mechanisms are urgently needed to further improve the identification of OA sources in eastern China.