Hamiltonian theory for the non-rigid Earth: Semidiurnal terms

The purpose of this paper is to determine the contributions to the nutation series arising from the triaxiality of a non-rigid Earth model composed of a rigid mantle and a liquid core. With this aim, the canonical formulation of the rotation of the non-rigid Earth developed by Getino and Ferrandiz i s applied in order to study the semidiurnal terms arising from the C-22 and S-22 geopotential coefficients. Once the corresponding generating function is calculated, analytical expressions of the Andoyer and figure planes are derived. We also provide numerical nutation series based on the analytical formulae.