Influence of Turbulence on an Essentially Nonlinear Dynamo Mechanism

Through direct numerical simulations, we study the influence of turbulence on a novel essentially nonlinear dynamo (END) mechanism. This dynamo operates through the interaction of a velocity shear with magnetic buoyancy mitigated by secondary Kelvin-Helmholtz instabilities. As opposed to the traditional mean-field or kinematic theory treatment, this END paradigm only exhibits dynamo action if the initial magnetic configuration is finite and above a critical threshold. We first study the effects of the smallest scales of turbulence by injecting noise into the magnetic fields. We then seek to study the effect of a wider range of scales by analyzing the interactions of actual resolved convection. To achieve a setup that is perhaps more realistic, we ultimately embed the END mechanism in a two-layer penetrative simulation. These preliminary results indicate that turbulence in many forms does little to hinder the END mechanism and therefore this example of an END at least appears to be quite robust.