## Fig nbsp xA The monthly average of ozone diurnal

Fig. 2. The annual power spectra of Wnt-C59 at Dongtan from 2008 to 2012 and at Baoshan, Pudong, Xujiahui and Jinshan from 2006 to 2012. The diagonal line shows − 5/3 power law.Figure optionsDownload full-size imageDownload as PowerPoint slide

4.1.1. Diurnal variation

Fig. 3 shows the time series of the normalized ozone wavelet spectrum at two of the five stations (Dongtan and Pudong). The results from the other three stations are similar. The normalized variance of the ozone diurnal variation (subsequently referred to as variance) fluctuates significantly with season, with higher values in summer and lower values in winter. There are some differences of the variance across the years; for example, the amplitudes in 2006 are smaller than those in other years.

Fig. 3. Wavelet spectra for ozone at Dongtan from 2008 to 2012 and at Pudong from 2006 to 2012.Figure optionsDownload full-size imageDownload as PowerPoint slide

Fig. 4. The monthly average of ozone diurnal variation variance at Dongtan from 2008 to 2012 and at Xujiahui, Pudong, Jinshan, Dongtan and Baoshan from 2006 to 2012.Figure optionsDownload full-size imageDownload as PowerPoint slide