The Internal Structure and Dynamics of Jupiter Unveiled by a High-Resolution Magnetic Field and Secular Variation Model

Research areas:
Year:
2022
Keywords:
magnetic field, secular variation, dynamo radius, Jupiter
Authors:
Journal:
Geophysical Research Letters
Volume:
49
Number:
15
Pages:
e2022GL098839
BibTex:
Note:
e2022GL098839 2022GL098839
Abstract:
Abstract Unique information about the dynamo process acting at Jupiter can be inferred by modeling and interpreting its magnetic field. Using the fluxgate magnetometer measurements acquired during the 4 years of the Juno mission, we derive a magnetic field model which describes simultaneously the main field and the secular variation (SV) up to spherical harmonic degrees 16 and 8, respectively. Apart from the Earth's, this is the first time another planetary magnetic field along with its time variation is described to such a high degree. We use properties of the power spectrum of the static field to infer the upper boundary of the dynamo convective region at 0.830 ± 0.022 Jupiter radius. The SV and correlation times are relatively comparable to the Earth's and indicate that the field is dominated by advection. The field and SV morphologies suggest zonal as well as non-zonal deep fluid motions.