Bivariate Wavelet Analysis of Asia Monsoon and ENSO

This paper employs some recently developed bivariate wavelet analysis techniques to study the correlation be-tween Asia monsoon and El Nino southern oscillation (ENSO). Various energy spectral densities are defined for wavelet transforms, analogous to those used in conventional Fourier analysis. Some comparisons are made by ap-plying both wavelet and Fourier spectral methods to the data. The wavelet analysis shows evidence of some relation-ship between Asia monsoon and ENSO, which the Fourier analysis resolves poorly. Correlation on several time scales, ranging from 2-4 years, 11 years, and 22 years, become apparent with the wavelet cross-spectrum. Finally, the wavelet cross-transform provides time localization of the distinctive features within the data record.