Polar motion of the triaxial nonrigid Earth and atmospheric excitation

The present study aims to extend the traditional rotation theory of the rotational-symmetric Earth to the triaxial Earth. We re-formulate the Liouville equations and their general solutions for the triaxial nonrigid Earth and find that the traditional theory introduces some theoretical errors in modeling the excitation functions. Furthermore, we apply that theory to the atmospheric excitation and find that theoretical errors should not be neglected given the present measurement accuracy. Thus we conclude that the traditional theory of the rotation of the rotational-symmetric Earth should be revised and upgraded to include the effects of the Earth’s triaxiality.