Correlations and periodicities in Himalayan tree ring widths and   temperature anomalies through wavelets
  We have studied periodicities and correlation properties of tree ring width chronology of deodar tree from Joshimath (1584 - 1999 years) and Uttarkashi (1500 - 2002 years) in the western Himalayas and the pre-monsoon (March-April-May) temperature anomalies (1876 - 2003) relative to 1961 -1990 mean, through wavelet analysis. Periodic behavior is observed in the tree ring chronology with periodicity in the form 11, 22, and 42 years. The analysis of the self-similar nature reveals long-range correlation with a Hurst exponent, $H >0.5$. These are anti-correlated with the temperature anomalies. An interesting inversion behavior is observed around the year 1750. The power spectral analysis of the time series corroborate the results of wavelet method. 
Prasanta K. Panigrahi, P. Manimaran, Ananth Lakhmi, and Ram R. Yadav