Here are presented the variation of polar motion (∆ X and ∆ Y) and length-of-day (∆LOD) for the time interval 1983 - 1997 the observed decadal variation (black dashed line), deduced from IERS time series, and compared forward modelled variation of the Earth's rotation (colored lines for different CMB topography models). Beside the electromagnetic and the topographic core-mantle coupling, atmospheric and oceanic excitations are considered for the forward modelling, which are computed by the ocean circulation model OMCT and the related atmospheric input data. The comparison shows the necessity of the extension of the time series as well as the additional consideration of the gravitational coupling processes in future investigations.
(Dr. J. Hagedoorn)
