Evolutionary spectral analysis of European climatic series

Five long historical time series of temperature and atmospheric pressure, with lengths from 149 to 279 years, three measured in Northern Italy and two in Sweden, were analyzed from the stationary and evolutionary spectral point of view, by means of the the Wavelet Transform and of the classical Fourier method. The main cyclicities revealed in the series of temperature showed interesting differences between the behaviors of Italian and Scandinavian stations. The time intervals in which each series exhibited in its wavelet spectrum a particularly important contribution by a given scale, or range of scales, were also studied. Opposite behaviors were found in Milan (Italy) and in Scandinavian stations, in the second half of the XXth century, as far as the coupling between temperature and pressure around a scale of 30 years is concerned.