Simulation Evaluation of the Contribution of Typical PM2.5 Pollution and Trans-regional Transport to Ningbo Pollution in the Yangtze River Delta

Abstract

The weather research and forecasting model (WRF) and the nested air quality prediction model system (NAQPMS) were used to simulate a typical heavy PM2.5 pollution event in the Yangtze River Delta (YRD) on January 10, 2015. The results showed that NAQPMS simulation accurately reproduced the development process of heavy PM2.5 pollution in the YRD. External regional pollution transport was a significant factor, primarily through three channels:the inland channel (Henan-Anhui-Jiangsu), coastal channel (Hebei-Shandong-Jiangsu), and ocean channel (Hebei-Shandong-Huanghai Sea-Jiangsu). The source apportionment of estimating the contribution across regions with Ningbo as the receptor showed that the coastal channel was the main channel in the pollution occurrence stage, and the large transport contribution was from Jiangsu (36.51%). The inland and ocean channels were more important in the heavy pollution stage, and the main external regional contributions were from Zhejiang North (25.55%), Anhui (12.33%), and the ocean (16.92%). Pollution dissipation was mainly affected by the ocean channel, and the main external contribution regions were Jiangsu (14.74%) and the sea (31.43%).