Analogy between the Drift Planetary Vortices and the Precession of a SpinningBody

摘要

The physical orgin of a well-known expression for the drift velocity of amonoploe vortex on a rotating planet is clarified. It is shown that this drift can be obtained from the equation of motion of a small, rotating disk on the surface of the planet. A rotating planet is slightly oblate, and in an inertial frame, there is a net force on the disk directed from the equator toward the closest pole. The drift along a latitude circle caused by this force is completely analogous to the precession of a spinning body.