Fluid Motions near the Core Boundary and the Irregular Variations in the Earth's Rotation.

Abstract

The transmission of mechanical forces of the magnetic field through the top layers of the core into mantle is studied. It is shown that moderate fluctuations of the toroidal field near the boundary of the core are large enough to produce the observed variations in the rate of rotation of the mantle. A simple theoretical analysis of the motions near the boundary of the core shows that the equations of the geostrophic wind in meteorology can be applied to the layer.