Towards an integrated anthropogenic emission inventory for China

The implementation of the Air Pollution Prevention and Action Plan (2013–2017) in China has led to a significant decrease in anthropogenic emissions. However, at the same time, ozone (O­₃), a secondary pollutant formed from nitrogen oxides (NO_x) and volatile organic compounds (VOCs) in the presence of sunlight, has increased in the large urban agglomerations of China. To better understand the reasons behind this increase, high-quality anthropogenic emission inventories are needed. In this study, we compared ozone precursor emissions in China from various anthropogenic emission inventories (EIs), including the national EI, Multi-resolution Emission Inventory for China (MEIC), and three global EIs from the Copernicus Atmosphere Monitoring Service (CAMs), Community Emission Data System (CEDS), and Hemispheric Transport of Air Pollution project (HTAP). Differences in emission magnitudes, trends, and spatial distributions were investigated. Global-scale and regional EIs were homogenized by sector and specie to obtain ‘harmonized’ EIs. These harmonized inventories were then used to drive WRF-Chem simulations for the winter and summer of 2017, and the results for each EI were evaluated against observations from the air quality monitoring network developed by the Ministry of Environmental Protection of China. The outcome of this study denotes that using harmonized regional and global EIs can significantly improve the performance of the numerical models when simulating the atmospheric composition of large agglomerations in China.