Impact of the Interannual Variability in Large-Scale Circulation on the Ground-Level Ozone Variability Over Eastern China

Abstract

Interannual variation in ozone pollution could vary greatly with large-scale circulations. Using empirical orthogonal function (EOF) and singular value decomposition (SVD), we statistically assess the impacts of large-scale circulations on seasonal and interannual variability of ground-level ozone in eastern China, by using the data from 2014 to 2019. The EOF results show three major variation patterns of ozone: the dominant seasonal variation pattern over the majority of eastern China, the anticorrelation between northern and southern China (NorthC and SouthC), and the ozone peaks in early spring over the coastal areas and Taiwan. Multiple linear regression results show that the first three modes of meteorological factors can explain 44%, 22%, and 11% of the ozone variability, respectively. Using SVD analyses between the ozone and meteorological data, it was found that there is a clear relationship between the seasonal and interannual variability of ground-level ozone over eastern China and the variability in the large-scale circulations, which revealed by the first three SVD modes and account for 95% of the total variance. The first SVD mode shows that the seasonal variation of ground-level ozone over eastern China is driven by the seasonal variation of solar radiation and East Asian summer monsoon. The second and third SVD modes show that the anti-correlation between the NorthC and SouthC, the ozone peaks in early spring over the coastal areas and Taiwan are largely influenced by western Pacific subtropical high and continental cold high events, respectively.