Using surface displacements to probe Venus’ interior structure and atmospheric dynamics

The circulation of fluid mass associated with Venus’ atmospheric dynamics leads to periodic changes in surface displacement and gravitational field. As deformation depends on its interior structure and the applied load, observations of the shape of Venus can help constrain models of solid-body structure and atmospheric dynamics. In this study, we investigate whether surface deformations associated with atmospheric loading are detectable from orbit. To this end, we combine a general circulation model of Venus’ atmosphere with a novel approach to the solution of the quasi-static momentum equations in the coupled gravito-elastic problem for a three-dimensional planet. We find that atmospheric loading produces surface displacements up to ±2 cm that may be detectable near equatorial regions by the VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) mission, which is expected to perform high-precision surface displacement measurements in specific locations. Complimentary to this, we explore whether surface displacement measurements can be employed to image surface pressure changes, which can be used to inform Global Climate Models of Venus and thereby advance our understanding of its atmosphere and, in turn, weather and climate. Finally, our results offer guidance for future mission design by establishing quantitative thresholds for surface displacement observations to be used to infer structural properties of Venus’ interior and its atmospheric dynamics.