About the article
Analysis had made of dynamics of the precipitation acidity (atmospheric precipitation had fallen in Tver in 1990–2020 years). Time series models of the indicator pH were examined. Cubic and quadratic models have considered as adequate. Seasonal indices of the indicator pH preserved his character in spite of time series lengthening.
acidity, acid rain, precipitation, model, time series, trend, cycle component, seasonal component, residuals, indicator pH.