Hydrodynamic modelling of dynamical tide dissipation in Jupiter’s interior as revealed by Juno

¹ Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France
e-mail: hachem.dhouib@cea.fr
² IRAP, Université de Toulouse, CNRS UMR 5277, UPS, 31400 Toulouse, France
³ Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France
⁴ Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK

Received: 11 August 2023
Accepted: 6 November 2023

Abstract

Context. The Juno spacecraft has acquired exceptionally precise data on Jupiter’s gravity field, offering invaluable insights into Jupiter’s tidal response, interior structure, and dynamics, establishing crucial constraints.

Aims. We aim to develop a new model for calculating Jupiter’s tidal response based on its latest interior model, while also examining the significance of different dissipation processes for the evolution of its system. We studied the dissipation of dynamical tides in Jupiter by thermal, viscous, and molecular diffusivities acting on gravito-inertial waves in stably stratified zones and inertial waves in convection ones.

Methods. We solved the linearised equations for the equilibrium tide. Next, we computed the dynamical tides using linear hydrodynamical simulations based on a spectral method. The Coriolis force is fully taken into account, but the centrifugal effect is neglected. We studied the dynamical tides occurring in Jupiter using internal structure models that respect Juno’s constraints. We specifically looked at the dominant quadrupolar tidal components, and our focus is on the frequency range that corresponds to the tidal frequencies associated with Jupiter’s Galilean satellites.

Results. By incorporating the different dissipation mechanisms, we calculated the total dissipation and determined the imaginary part of the tidal Love number. We find a significant frequency dependence in dissipation spectra, indicating a strong relationship between dissipation and forcing frequency. Furthermore, our analysis reveals that, in the chosen parameter regime in which kinematic viscosity and thermal and molecular diffusivities are equal, the dominant mechanism contributing to dissipation is viscosity, exceeding both thermal and chemical dissipation in magnitude. We find that the presence of stably stratified zones plays an important role in explaining the high dissipation observed in Jupiter.