Simulated Dataset of Io's Love Numbers and Libration Amplitudes for a Dynamically Coupled Melt-Rheology Framework

Abstract: This repository contains a simulated dataset of tidal parameters (Love numbers $k_2$, $h_2$ , $l_2$ ) and libration amplitudes for the Jovian satellite Io. The data investigate the coupling between material rheology and melt fraction under different internal structure assumptions. Methodology: The results were obtained using a modified version of the California Planetary Geophysics Code (CPGC) (Ermakov & Akiba, 2024), adapted to implement a self-consistent feedback loop between material rheology and melt fraction (Bierson & Nimmo, 2016). Calculations were performed considering both incompressible and compressible internal structures. Model Scenarios: The dataset explores various physical parameters, including the radial position of the onset of melting $R_{\phi0}$, the latent heat of fusion $L$, and the initial Andrade parameter $\beta_0$. Mantle properties - viscosity $\eta$, shear modulus $\mu$, and the Andrade parameter ($\beta$) - are iteratively updated based on the local melt fraction $\phi(r)$ (Moore, 2001). Our analysis reveals that although the deep mantle serves as the primary region for tidal heating, a distinct shallow-mantle enhancement emerges self-consistently. The modeled presence of melt decreases the effective viscosity and increases anelasticity, directly driving up tidal dissipation in the upper mantle. Structural Assumptions: Each model assumes a liquid core, an Andrade viscoelastic mantle discretized into 67 sublayers, and an elastic crust.