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 for accurately calculating the tidal response of Jupiter for a given interior model and to investigate the role of 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 can simultaneously obtain the real and imaginary parts of the tidal Love numbers for a given planetary interior model. Results. We calculate the tidal responses for three simple interior models of Jupiter which may contain a compact rigid core or an extended dilute core. All of models we consider can explain the fractional correction $\Delta k_{22}\approx -4\%$ due to dynamical tides, but all have difficulties to reconcile the observed $\Delta k_{42}\approx -11\%$ 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 a thin stable layer in the outer region, if exists, would also influence the tidal responses of Jupiter.