Prediction of PM2.5 concentrations during winter in East Asia using climate indices

The synoptic meteorological field plays an important role in the daily-scale PM_2.5 variability in East Asia. Since East Asia is located on the eastern boundary of the Eurasian continent, the expansion and contraction of the Siberian high-pressure system act as an essential mechanism for determining surface PM_2.5 concentrations in the winter season. Here, we select four climate indices representing the variability of the Siberian high-pressure system and analyze the correlation with the daily variability of the observed winter PM_2.5 concentrations in China and South Korea over the past six years. Siberian High Intensity and East Asian Winter Monsoon indices showed a more pronounced correlation with the daily surface PM_2.5 concentration changes, and the daily surface PM_2.5 concentrations in North China Plain showed a maximum change of ±40 μg m^-3 after exceeding the threshold (+1 or −1). The climate indices associated with the Siberian high-pressure system can effectively predict daily PM_2.5 concentrations in East Asia within a week.