Large scale magnetic field generation via inertial wave dynamo

Measurements from the Galileo probe indicate a large scale magnetic field of 750 nT on Ganymede, one of Jupiter's moons. This magnetic field far exceeds the strength which could be generated by a dynamo driven by compositional and thermal convection, such as that which generates the Earth's magnetic field. This work investigates the feasibility of an inertial wave dynamo in generating large scale magnetic field in such a body. In this framework, inertial waves, those whose restoring force is the Coriolis force, are responsible for generating a large scale magnetic field providing only waves propagating in one direction are present. We utilize a novel 2D eigenvalue solver to determine the growth rate of the magnetic energy in such a system, and compare to predictions given by asymptotic theory in Moffatt (1970).