Exchange of angular momentum between the core and the mantle

Abstract

Exchanges of angular momentum between the core and the mantle responsible of the so-called decade variations in the length of the day (l.o.d.) are reexamined. It is proposed that, for the relevant time constants, the changes in the core angular momentum are carried by cylindrical annuli rigidly rotating around the Earth's rotation axis. Then the possible coupling mechanisms are discussed. A mechanism is presented which can reduce this torque down to values compatible with l.o.d. data. -from Authors