Emission inventory evaluation using observations of regional atmospheric background stations of China

Any accurate simulation of regional air quality by numerical models entails accurate and up-to-date emissions data for that region. The INTEX-B2006 (I06), one of the newest emission inventories recently popularly used in China and East Asia, has been assessed using the Community Multiscale Air Quality model and observations from regional atmospheric background stations of China. Comparisons of the model results with the observations for the species SO₂, NO₂, O₃ and CO from the three regional atmospheric background stations of Shangdianzi, Longfengshan and Linan show that the model can basically capture the temporal characteristics of observations such as the monthly, seasonal and diurnal variance trends. Compared to the other three species, the simulated CO values were grossly underestimated by about two-third or one-half of the observed values, related to the uncertainty in CO emissions. Compared to the other two stations, Shangdianzi had poorer simulations, especially for SO₂ and CO, which partly resulted from the site location close to local emission sources from the Beijing area; and the regional inventory used was not capable of capturing the influencing factors of strong regional sources on stations. Generally, the fact that summer gave poor simulation, especially for SO₂ and O₃, might partly relate to poor simulations of meteorological fields such as temperature and wind.