Power spectrum analysis of atmospheric ozone during the summer

Summary This paper describes a study of the fluctuations in total atmospheric ozone amount as measured with a Dobson Spectrophotometer during the summer season over three north Indian stations, using the technique of power spectrum analysis. In all 19 spectra have been constructed. The long term trend was removed by applying a high pass filter. The main conclusions are: (1) The nature of the spectrum at a station generally differs from year to year. (2) Spectra of different stations during the same year, are generally different. (3) From the significance study of the spectral peaks, most of the spectra revealed the presence of two types of periodicities. One of these is in the range of 10–17 days while the other is found to have a range of 4.5–8.3 days. (4) It has been suggested that the former periodicity may be closely linked to the index cycle, while the latter may be related to the long waves in the Westerlies.