北京师范大学全球变化与地球系统科学研究院
北京师范大学全球变化与地球系统科学研究院
   
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            Zhihua Zhang.
College of Global Change and Earth System Science, Beijing Normal University.
            Palle E. T. Jorgensen. Department of Mathematics, University of Iowa, Iowa City, IA, 52242, USA.

Abstract

We model background noise in time series of climate data as AR(1) red noise. To extract significant features of these time series, we use comparisons of wavelet power spectrum time series with that of AR(1) red noise. We improve on earlier work which has so far only relied on empirical formulas for the distribution of AR(1) red noise in Morlet wavelet power spectrum; see Torrence and Compo (Bull. Am. Meteorol. Soc. 79:61–78,
1998). Although wavelet phase distributions do play an important role in analysis of causal relations in climate time series, up to now, the wavelet phase distribution of AR(1) red noise has not been rigorously established for wavelet transforms. In this paper, we derive the formulas for both the wavelet power spectrum distribution, and the wavelet phase distribution of modulated Haar wavelet background noise. We give rigorous proofs.

Keywords:
Climatic background noise Wavelet power spectrum Wavelet phase Haar wavelet