Dominant climate drivers of wintertime severe particulate pollution in North China

Abstract Severe particulate pollution days (SPPDs, characterized by a daily mean PM2.5 concentration exceeding 150 μg m-3), which are extremely harmful to human health and the environment, occurred frequently in North China during the boreal winters of 2013–2019. SPPDs generally occur under conducive weather patterns (CWPs) characterized by a weakened East Asian Trough in the mid-troposphere, reduced winter northerlies in the lower troposphere, and a temperature inversion at the surface. The occurrence of CWPs has been attributed to variations in numerous climate factors (e.g., Arctic sea ice cover, sea surface temperature, and atmospheric teleconnections), but the dominant climate drivers remain inconclusive. Here, we show that the East Atlantic-West Russia (EA/WR) teleconnection pattern and the Victoria Mode (VM) of sea surface temperature anomalies are the first and second dominant climate drivers, respectively, leading to CWPs in North China through the zonal and meridional propagations of Rossby waves and explaining 36.3% and 18.5%, respectively, of the observed wintertime SPPDs in Beijing-Tianjin-Hebei. Our results suggest that, with the help of seasonal forecast from climate models, the indices of the EA/WR and VM can be used to predict wintertime SPPDs over Beijing-Tianjin-Hebei.