Simulation analysis of atmospheric SO2 contributions from different regions in China

Abstract

Abstract Sulfur dioxide (SO2) is an atmospheric pollution source that poses a threat to the environment and human health. Investigating atmospheric SO2 contributions between different regions will help to reduce SO2 emissions and control pollution. Using the weather research and forecasting (WRF) model and the community multiscale air quality (CMAQ) modeling system, as well as the intercontinental chemical transport experiment phase B (INTEX-B) data, we analyzed the regional contributions of atmospheric SO2 in China. The results showed that SO2 contributions varied significantly between regions and seasons. The atmospheric SO2 levels in Central China (CTR) originated mostly from self-emissions, accounting for as much as 60% of the total emissions in January and April and up to 85% in July and October. The SO2 concentrations in Northeast China (NE) were mainly affected by emissions from CTR, especially in January (39.53%). SO2 concentrations in Northwest China (NW) were mainly affected by external emissions, which exceeded half of the SO2 in this region. SO2 concentrations in Southwest China (SW) were dominated by self-emissions, which accounted for more than 90% of the total SO2. In terms of seasons, SO2 concentrations were significantly affected by external emissions in January and April and were dominated by self-emissions in July and October. Coal use, population, area, and thermal power were found to have the greatest impacts on SO2 concentrations. Among these, coal consumption had the biggest impact on the national SO2 concentration.