Analysis of similarity of several proxy series based on nonlinear analysis method

Abstract

Reconstruction and analysis of proxy series is an important program of climate research. Using methods of wavelet transformation and power spectrum, the main periods of Dulan tree ring and other 7 temperature proxy series are analyzed in this paper. Through filtering, the 8 original series were divided into many different scale components, the similarities in dynamics and external features of components on each scale are studied based on the dynamical correlation factor exponent and correlation coefficient. Research results show that quasi 100a scale might be the common period of these proxy series, meanwhile, both dynamics and external features of these proxy series are similar on the quasi 100a and even higher scales. This means that the quasi 100a and even higher scale components meet with comparable conditions in these aspects. More attention must be paid to this scale when analyzing proxy series. We also found that the similarities in dynamics and external features of these proxy series are reduced as the scale of the components decreaces; On quasi 60—70a scale, the component similarities in dynamics features disappear. On quasi 30a and even lower scale the similarities of external features also disappear.