Earth rotation changes due to the core; core-mantle coupling (2)

electromagnetic torque:

• poloidal torque, related to the electric current associated with the poloidal magnetic field, deduced from surface observation of Br ;
• advective torque, related to the flow and the poloidal magnetic field at the CMB, can be computed from surface observation of Br and hypotheses for the flow;
• leakage torque, related to the electric current from diffusion of the core toroidal magnetic field into mantle, cannot be deduced from surface observation;