Decadal modulation in length-of-day variations from solar activity: a wavelet approach

In this present paper, wavelet technique is applied to analyse the time series of the Earth´s length-of-day series during 1832-1997 and the sunspot relative numbers during 1700-2006, with emphasis on investigating external excitation source of the Earth´s variable rotation. The results show modulation action from solar activity plays an important role in decadal change of the Earth rotation, and this strengthens the conclusion that the Earth´s rotation is modulated by the solar activity.