Response and periodic variation of total atmospheric ozone to solar activity over Mountain Waliguan

Abstract

Modern-Era Retrospective Analysis for Research and Applications, Version-2 (MERRA-2) total column ozone (TCO) data from 1980 to 2018 and ground based TCO data were used to investigate its responses to periodic variations concerning stratospheric dynamics such as tropopause heights and Quasi-Biennial Oscillations (QBO), and solar activity signatures of Magnesium II core-to-wing ratio (Mg II) and F10.7 cm solar radio flux (F10.7) observed over Mountain (Mt.) Waliguan (36.17°N, 100.53°E), China. Cross-correlation and wavelet analyses were used for carrying out the investigation. The MgII and F10.7 show a periodicity of around an 11-year solar cycle (SC) while the TCO trend is though periodic and it does not exhibit one to one correspondence with the 11-year SC. The highest value in TCO is 355.7 DU noted in February (1982) whereas, the lowest value of TCO is 256.02 DU in October (1988) during the entire study period. The average value in TCO is 291.17 ± 0.94 DU with an amplitude of variation of 99.68 DU (~28%). The trend of TCO depicts a persistent distinct seasonal pattern with maxima in winter/spring (December through April) and minima in summer/autumn (August through November). The long-term variability shows a notable decreasing trend in TCO by ~30%, 13%, and 5% per decade for SCs 21–23, where SC 24 represents an increasing trend of ~1% per decade. Hence, this illustrates the significant recovery of TCO over Mt. Waliguan, China which is as a result of the reduction of the ozone depletion agents arising as a positive outcome of the implementation of the Montreal regulatory policy. From wavelet analysis, the F10.7, MgII, tropopause height, QBO and TCO show a significant dominant periodicity of 10–12 months. It is concluded that the variations in mean TCO are strongly correlated with variations of the F10.7 cm and Mg-II solar indices, and the mean TCO responds rapidly to solar activity variations.