On the gravitational signature of zonal flows in Jupiter-like planets: An analytical solution and its numerical validation
Physics of the Earth and Planetary Interiors
Reason for embargo
In late 2016, the Juno spacecraft will provide an accurate spectrum of the Jovian zonal gravitational coefficients that would be affected by both the deep zonal flow, if it exists, and the basic rotational distortion. We derive the first analytical solution, under the spheroidal-shape approximation, for the density anomaly induced by an internal zonal flow in rapidly rotating Jupiter-like planets. We compare the density anomaly of the analytical solution to that obtained from a fully numerical solution based on a three-dimensional finite element method; the two show excellent agreement. We apply the analytical solution to a rapidly rotating Jupiter-like planet and show that there exists a close relationship between the spatial structure of the zonal flow and the spectrum of zonal gravitational coefficients. We check the accuracy of the spheroidal-shape approximation by computing both the spheroidal and non-spheroidal solutions with exactly the same physical parameters. We also discuss implications of the new analytical solution for interpreting the future high-precision gravitational measurements of the Juno spacecraft.
KZ is supported by Leverhulme Trust Research Project Grant RPG-2015-096 and by Macau FDCT grants 039/2013/A2 and 007/2016/A1. The computation made use of the high performance computing resources in the Core Facility for Advanced Research Computing at Shanghai Astronomical Observatory, Chinese Academy of Sciences.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.