Driving Factors of PM2.5 Pollution Rebound in North China Plain in Early 2023

Abstract

An unexpected rebound in PM_2.5 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 PM_2.5 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 PM_2.5 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 NO_X, 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.