Multy-year cycles observed in air temperature data and proxy series

First, palaeoclimatic time series are analyzed under the lens of the continuous wavelet transform. Two cycles, of period 30 and 43 months respectively, are detected in millennial temperature reconstructions. These rhythms correspond to the ones detected in weather station temperature records in a previous study of the authors. It is then showed that most parts of the globe are affected by at least one of the two cycles. Their relationship with the main climatic indices is also investigated, as well as the statistical significance of the observations.