Dynamical tides in Jupiter and the role of interior structure

Abstract

Context. The Juno spacecraft has obtained highly accurate tidal Love numbers, which provide important constraints on the tidal response and interior structure of Jupiter. Aims. In order to exploit these observations, it is necessary to develop an approach to accurately calculate the tidal response of Jupiter for a given interior model and to investigate the role of the interior structure. Methods. We directly solve the linearized tidal equations of a compressible, self-gravitating, rotating, and viscous fluid body using a pseudo-spectral method. The Coriolis force is fully taken into account, but the centrifugal effect is neglected. We are able to simultaneously obtain the real and imaginary parts of the tidal Love numbers for a given planetary interior model. Results. We calculated the tidal responses for three simplified interior models of Jupiter which may contain a compact rigid core or an extended dilute core. All of the models we consider can explain the fractional correction ∆k22 ≈ −4% due to dynamical tides, but they all have difficulties reconciling the observed ∆k42 ≈ −11% for the high-degree tidal Love number. We show that the Coriolis force significantly modifies gravity modes in an extended dilute core at the tidal frequency relevant to the Galilean satellites. We demonstrate that the existence of a thin stable layer in the outer region would also influence the tidal responses of Jupiter.