Hydrodynamic modelling of dynamical tides dissipation in Jupiter's interior as revealed by Juno

TL;DR

This study models Jupiter's tidal response using interior data from Juno, revealing how different dissipation processes affect tidal energy loss, with viscosity being the dominant mechanism in stably stratified zones.

Contribution

We develop a comprehensive model of Jupiter's dynamical tide dissipation incorporating multiple physical processes and Juno's interior constraints, advancing understanding of tidal dissipation mechanisms.

Findings

Viscosity dominates dissipation over thermal and chemical processes.

Dissipation spectra show strong frequency dependence.

Stably stratified zones significantly influence high dissipation levels.

Abstract

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. We 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 study 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. We solve the linearised equations for the equilibrium tide. Next, we compute 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 study the dynamical tides occurring in Jupiter using internal structure models that respect Juno's constraints. We study specifically 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. By incorporating the different dissipation mechanisms, we calculate the total dissipation and determine 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, thermal and molecular diffusivities are equal, the dominant mechanism contributing to dissipation is viscosity, exceeding in magnitude both thermal and chemical dissipation. We find that the presence of stably stratified zones plays an important role in explaining the high dissipation observed in Jupiter.