Driving Factors of PM_2.5 Pollution Rebound in North China Plain in Early 2023

An unexpected rebound in PM2.5 pollution was observed in the North China Plain (NCP) during the post-COVID-19 period in 2023 compared to 2022. Identifying the driving factors behind this phenomenon is critical for developing PM2.5 mitigation strategies. In this study, the Community Multiscale Air Quality (CMAQ) model, coupled with near-real-time emission inventories, was utilized to quantify the contributions of meteorological conditions and anthropogenic emissions to the severe PM2.5 rebound observed in February 2023. The results revealed that anthropogenic emissions and meteorological factors accounted for 59% and 41% of the rebound, respectively. Increased activities in transportation, domestic combustion, and power and industrial sectors significantly elevated NOX, SO2, and primary particulate emissions. Key meteorological drivers included higher relative humidity, reduced wind speed, and a lower atmospheric boundary layer height, which were linked to anomalous southerly wind patterns over the NCP. This study underscores the pivotal role of transitioning energy and industrial structures in fostering a green economic recovery, which is crucial for achieving sustained and substantial improvements in air quality over the NCP.