Statistical analysis and comparison of external factor effects on the total ozone field over the Russian territory in 1973–2007

Abstract

The analysis of external factors, which are most significant for the formation of the monthly mean total ozone (TO) field and ozone transport over the Russian Federation, based on observation data obtained from about 30 ground-based stations of the ozonometric network averaged over a year, December through March and June through August, over five climatic regions, is considered. Performed spectrum and discriminant analysis allowed obtaining quantitative estimates of the impact of the Arctic Oscillation, deviation of the winter temperature of the lower polar stratosphere, quasi-biennial oscillations (QBO), 11-year solar cycle, El Nino-Southern Oscillation (ENSO) on the TO and to assess the regional differences in the effects of these factors. In December–March, in the years with a negative Arctic Oscillation phase, warm stratosphere, and the easterly QBO phase (QBO-E), the ozone content increases significantly relative to the opposite phases of oscillations on average by 35, 28, and 26 Dobson units (DU), respectively. The spectra, similar to the discriminant function, demonstrate strong influence of the 11-year solar cycle and QBO on the TO even in the summer months, while the QBO is more pronounced in the eastern part of the Russian Federation. The ENSO effect was not singled out against the general “noisy” background of the cold six-month period, when many atmospheric processes become active: however, during the summer months, in warm periods of the ENSO, the TO, at the 97% significance level, increases over most of the Russian area. The rest of the obtained results are significant at the 95–99.9% level.