Published online by Cambridge University Press: 12 April 2016
This paper discusses the short-period terms of nutation which are included in the recent theories of nutation for a rigid Earth. We argue that these terms should be expressed as terrestrial perturbations, that is as polar motion, and describe how such a transformation can be accomplished in practice. Based on the available rigid-Earth amplitudes, we estimate this lunisolar effect in polar motion for an elastic Earth with liquid core, and compare it to the oceanic and atmospheric perturbations at similar frequencies.