Monday 21 Jan 2019: Force balance in convectively driven dynamos with no inertia
Prof. David Hughes - University of Leeds
Harrison 103 14:30-16:30
It is generally believed that the Earth’s dynamo operates in the strong field regime, in which the nature of the convection is very different to that in the absence of magnetic field. That said, accessing the strong field regime computationally has proven difficult. Here we consider dynamos driven by rotating convection in which inertia is neglected, but viscous terms are retained. This system supports both weak and strong field dynamos, which can be analysed by exploiting the linearity (with no inertia) of the momentum equation. We consider the issue of the force balance in such dynamos and also address the issue of Taylor’s constraint and how closely this is satisfied in a system with ostensibly small viscosity.