The magnetic fields of Uranus and Neptune are unique in the Solar System in that they are not dominated by their axial dipole components. Using numerical dynamo simulations, we have investigated mechanisms whereby Uranus and Neptune could generate these complex, multipolar fields. Relevant papers include:

• Tian, B.Y. & Stanley, S., “Interior structure of water planets: Implications for their dynamo source regions”, Astrophys. J. 768, 156 (2013).

• Stanley, S. and Bloxham, J., Numerical dynamo models of Uranus’ and Neptune’s magnetic fields, Icarus, 184, 556-572 (2006).

• Stanley, S. and Bloxham, J., Convective-region geometry as the cause of Uranus’ and Neptune’s unusual magnetic fields, Nature, 428, 151-153 (2004).