Towards an integrated inventory of anthropogenic emissions for China

Abstract. Despite ongoing efforts to reduce pollution, persistent ozone pollution in China remains a public health concern. To better understand the causes of ozone pollution in China and to assess and evaluate the effectiveness of past, current, and planned targeted pollution control strategies, estimates of the amounts of pollutants emitted from various sources are needed. To this end, we have developed harmonized and integrated anthropogenic emission inventories for China, incorporating information from the existing national inventory for mainland China (MEIC) and three global inventories (CEDS, CAMS, HTAP) to cover areas outside of China. The newly developed China INtegrated Emission Inventory (CINEI) includes emissions in China from sectors currently omitted from the MEIC (ships, aviation, waste, and agriculture) that we incorporate from the global inventories. To ensure harmonized emissions data, we performed mapping between different inventories, a process used to achieve consistency between sectors, spatial resolution, and speciation of non-methane volatile organic compounds (NMVOCs). These harmonized and integrated inventories for China were used to drive WRF-Chem simulations for January (winter) and July 2017 (summer). Through a detailed evaluation of model results against available observations, we show that while the direct use of global inventories alone can lead to severe over- or underestimation of pollutant mixing ratios, CINEI inventories perform satisfactorily in simulating ozone (12 % in summer and 43 % in winter normalized mean bias) and its precursors, including nitrogen dioxide (NO₂, -0.5 % in summer and 40 % in winter) and carbon monoxide (CO, -50 % in both seasons). Based on the comparison and modeling of this study, valuable insights into the spatio-temporal variability of ozone and the subsequent design of future ozone mitigation strategies in China were provided.