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The Juno mission will measure Jupiter's magnetic field with unprecedentedprecision and provide a wealth of additional data that will allow to constrainthe planet's interior structure and dynamics. Here we analyse 66 numericalsimulations in order to explore the sensitivity of the dynamo-generatedmagnetic field to the planets interior properties. The degree l=4 field modelVIP4 and up-to-date interior models based on ab initio simulations serve asbenchmarks. Our results suggest that VIP4-like magnetic fields can be found fora number of different models. We find that whether we assume an ideal gas oruse the more realistic interior model based on ab initio simulations makes nodifference. However, two other factors are important. Low Rayleigh number leadsto strong axial dipole contribution while the axial dipole dominance is lostwhen the convective driving is too strong. The required intermediate range thatyields Jupiter-like magnetic fields depends on the other system properties. Thesecond factor is the convective magnetic Reynolds number profile Rmc(r), aproduct of the non-axisymmetric flow velocity and electrical conductivity. Wefind that the depth where Rmc exceeds about 50 is a good proxy for the top ofthe dynamo region. When the dynamo region sits too deep, the axial dipole isonce more too dominant due to geometric reasons. We extrapolated our results toJupiter and the result suggests that the Jovian dynamo extends to 95% of theplanetary radius.  The zonal flows in our simulations are dominated by an equatorial jet largelyconfined to the molecular layer. Where the jet reaches down to higherelectrical conductivities, it is gives rise to a secondary alpha-Omega dynamothat modifies the dipole-dominated field produced deeper in the planet. Thissecondary dynamo can lead to strong magnetic field patches at low latitudesthat seem compatible with the VIP4 model.

Physical conditions for Jupiter-like dynamo models