The LOD (length of day) and $X3 spectra were computed using the maximum entropy method (MEM). The comparisons show excellent correlation between the axial component of the atmospheric EAMF ($\chi_{3}$) and the changes in the Earth's rotation rate corrected for the effects of the lunar and solar tides. The most important changes are the seasonal variations with annual and semi-annual periods, and a cluster of small peaks with periods between 40 and 70 days i both spectra (LOD and $\chi_{3}$).