Tidal dissipation with 3D finite element deformation code CitcomSVE v2.1: comparisons with the semi-analytical approach

Abstract Different methods are possible for estimating the tidal deformations of Earth and telluric planets. On one hand, the semi-analytical code ALMA³ solves analytically the governing equations in considering symmetrical and incompressible bodies with homogeneous layers and different possible rheologies. The tidal deformations are considered with period excitation functions and the output of the model is frequency-dependent complex Love numbers. On the other hand, the 3D finite element CitcomSVE integrates numerically the governing equations with possibly 3D viscosity and viscoelastic structures on the regional and global scales. In this work, we present how the tidal deformations have been implemented in CitcomSVE by the introduction of a periodic forcing potential. For validation and benchmarking, we realized comparisons between the semi-analytical ALMA³ output for tidal deformations and the numerical CitcomSVE in terms of frequency-dependent Love numbers k₂ and h₂ real and imaginary parts with 1D viscoelastic structure. We investigated comparisons of the frequency-dependent quality factor deduced from ALMA³ and from the CitcomSVE, We found that with a sufficient numerical resolution for CitcomSVE, the results of the two methods for computing tidal deformations (i.e., k₂ and h₂) and quality factor Q are in good agreement for different periods including the monthly period. We also computed tidal dissipation energy from CitcomSVE and found it consistent with that expected from quality factor calculation. Our study demonstrates the potential for CitcomSVE to be applied for planetary tidal deformation calculations for a planet with a 3D structure.