Logo image
Back
Numerical models of ice giant interiors
Dissertation   Open access

Numerical models of ice giant interiors

Dustin Jay Hill
Doctor of Philosophy (Ph.D.), Drexel University
Dec 2021
DOI:
https://doi.org/10.17918/00000900
pdf
Hill_Dustin_202178.55 MBDownloadView
PDF Open Access Open Access (License Unspecified)

Abstract

Planetary science Hydrodynamics Magnetohydrodynamics
Planetary magnetic fields are an important source of information about interior processes that are otherwise unobservable. Uranus and Neptune were discovered to have magnetic fields in the 1980s after encounters with Voyager 2. Unlike the other giant planets of the solar system, Uranus and Neptune have non-dipolar, non-axisymmetric magnetic fields. The results of previous numerical experiments are able to account for such magnetic fields through strongly driven convection. However, another property that Uranus and Neptune share are smaller internal heat sources than the other giant planets. In this work, we test the hypothesis that convection that is driven either entirely or partially by a chemical source in the deep interior is able to account for dynamic, thermal, and magnetic properties of the ice giant planets. To do so we introduce a set of numerical models including both rotating convection and self-consistent dynamos, that vary the relative contribution of thermal and compositional convection, including double-diffusive convection models. We find that these models are generally able to produce velocity fields that are similar qualitatively to the observed zonal winds of the ice giants, as well as multi-polar magnetic fields. By displacing thermally driven convection with compositionally driven convection, we demonstrate the possibility that the ice giants may undergo sufficiently vigorous convection to both drive zonal flows and to sustain the magnetic field without introducing a large heat flux.

Metrics

21 File views/ downloads
65 Record Views

Details

Logo image