Abstract:

The spatiotemporal characteristics of fine particulate matter (PM_2.5) concentration over the Yangtze River Delta in 2018 were simulated using the third-generation air quality forecast model, Long Term Ozone Simulation-European Operational Smog (LOTOS-EUROS). Comparing with ground observations, the rationality of this model to simulate the long-term characteristics of PM_2.5concentration was verified, and the spatiotemporal variation of PM_2.5 in this region was explored. The results showed that the LOTOS-EUROS model can well reproduce the spatiotemporal characteristics of PM_2.5 concentration in the Yangtze River Delta. The overall correlation coefficient between the observation and simulation values of the monitoring stations reaches 0.64, which means that this model can be applied to the simulation of fine particulate matter in the Yangtze River Delta. The PM_2.5 concentration in the Yangtze River Delta is high in winter of the northwest, and is low in summer of the southeast. High PM_2.5 concentrations in winter occur in the northwestern region of the Yangtze River Delta, and the maximum concentrationin in Anhui province and other areas can reach 160 μg·m^-3. In spring and autumn, high PM_2.5 concentrations are concentrated in the north of 30°N and the west of 120°E, with values ranging from 40 μg·m^-3 to 80 μg·m^-3. Whereas in summer, PM_2.5 concentration decreases significantly and remains around 20-40 μg·m^-3 in most areas. The low-value center of PM_2.5 concentration (lower than 10 μg·m^-3) occurs in coastal cities in the southeast of the Yangtze River Delta, with the lowest value reaching 5 μg·m^-3.

Key words: The Yangtze River Delta, Air quality prediction, Numerical simulation