On Viscosity Estimates for the Earth's Fluid Outer Core and Core-Mantle Coupling

Abstract

The kinematic viscosity of the Earth's fluid core is uncertain because estimates inferred from studies of liquid metals and from real-Earth measurements differ significantly. The role of dynamic effects is invoked in an attempt to reconcile this conflict. The implications of these additional effects for the coupling between a fluid and its container are discussed with respect to the nearly-diurnal free wobble and the free core nutation, which depend on the properties of the fluid core near the core-mantle boundary.