Application of EMD and wavelet method to sunspot data

The sunspot is one of the main cause of climate change. Research on the sunspot cycle is conducive to study climate change. Based on new approach, using time series analysis technique, empirical mode decomposition (EMD) and wavelet, to reveal the detail features of the variability of sunspot data on various time scales. In comparison with wavelet transform, EMD can analyze non-stationary and non-linear time series data and reveal the main characteristics of time series on time-frequency domains precisely.