Spherical convective dynamos in the rapidly rotating asymptotic regime

摘要: Self-sustained convective dynamos in planetary systems operate an asymptotic regime of rapid rotation, where a balance is thought to hold between the Coriolis, pressure, buoyancy and Lorentz forces (the MAC balance). Classical numerical solutions have previously been obtained moderate rotation viscous inertial are still significant. We define uni-dimensional path parameter space classical models conditions from requirements enforce preserve ratio magnetic diffusion overturn times Reynolds number). Direct simulations performed along this show that spatial structure solution at scales larger than dissipation length largely invariant. This enables definition large-eddy resting on assumption small-scale details hydrodynamic turbulence irrelevant determination large-scale state. These shown be good agreement with direct range both feasible, can computed for control values far beyond current state art, such as Ekman number . obtain strong-field approaching Taylor unprecedented degree accuracy. The physical connection devoid abrupt transitions, demonstrating relevance dynamo mechanisms. fields system confirmed follow diffusivity-free, power-based scaling laws path.