A recent emission inventory of S/IVOCs with high-resolution and evaluation in the Yangtze River Delta region of China

Semi-volatile and intermediate volatility organic compounds (S/IVOCs), as the key precursors, play an important role in forming secondary organic aerosol (SOA). However, the absence of S/IVOCs in the model has led to a significant gap between simulation and measurement of SOA. Although the emission inventory of S/IVOCs is prerequisite for improving the performance of SOA simulation and evaluating the roles of S/IVOCs in SOA production, a gridded anthropogenic emission inventory of S/IVOCs in the Yangtze River Delta (YRD) region is still limited. Therefore, a 2021-based high spatiotemporal resolution S/IVOCs emission inventory over the YRD region was developed in this study. The total emission of S/IVOCs for the YRD region was estimated to be 457.58 Gg. The industrial process was the major contributor to total emissions in Shanghai City, Anhui, and Jiangsu provinces with contributions of more than 40%, while on-road mobile sources contributed the most to S/IVOCs emissions in Zhejiang Province. High S/IVOCs emissions were mainly distributed in the central cities of the YRD with developed industry and transportation, such as Wuhu and Suzhou (Jiangsu), and in the northern cities with larger cultivated areas, such as Xuzhou and Yancheng. The uncertainty range of S/IVOCs emissions established in this study was −68%∼214%. Industrial process, industrial combustion, and on-road mobile were the sources with higher uncertainties of S/IVOCs emissions. A comprehensive S/IVOCs emission inventory established in this study can be used to estimate the emissions of S/IVOCs in 41 cities over the YRD region and can be applied to air quality models for a better understanding of the formation mechanism of SOA over the YRD region. • The 3 km × 3 km gridded S/IVOCs emission inventory was developed based on county-level activity data over YRD region. • Industrial process was the top contributor to S/IVOC emissions in the YRD region. • High S/IVOC emissions were mainly concentrated in central YRD areas with developed industry and transportation.