Fig. 2: The KZA filter result of PAN and O3.
From: Trends of peroxyacetyl nitrate and its impact on ozone over 2018–2022 in urban atmosphere
The panel numbers of (a, e), (b, f), (c, g) and (d, h) are the original time series, the short-term variations, the seasonal variations and the long-term trend of PAN and O3, respectively. The average correlation (R) between PAN and O3 in different kinds of series are 0.50, 0.59, 0.21, and −0.83, respectively. Note that the black dash lines show the 95% confidence intervals, the black text is the rate of change with lower value and upper value (ppb/year), and *** indicates the significance level p < 0.001.
