Reconstructions of Jupiter’s magnetic field using physics-informed neural networks

Magnetic sounding using data collected from the Juno mission can be used to provide constraints on Jupiter’s interior. However, inwards continuation of reconstructions assuming zero electrical conductivity and a representation in spherical harmonics are limited by the enhancement of noise at small scales. Here we describe new time-independent reconstructions of Jupiter’s internal magnetic field based on physics-informed neural networks and either the first 33 (PINN33) or the first 50 (PINN50) of Juno’s orbits. The method can resolve local structures, and allows for weak ambient electrical currents. Our models are not hampered by noise amplification at depth, and provide a smooth picture of the interior structure without explicit regularization. We estimate that the dynamo boundary is at a fractional radius of 0.8. At this depth, the magnetic field is arranged into longitudinal bands, and strong local features such as the great blue spot appear to be rooted in neighbouring structures of oppositely signed flux.