Earth rotation changes due to the core; core-mantle coupling (3)

New method for computing the electromagnetic torque (Wicht & Jault, 2000):

• frozen flux + additional constraint on the flow (on core angular momentum) from the agreement between LOD variations and temporal variations of the magnetic field;
• mantle conductivity as
  • power a law in conductive layer in mantle,
  • 0 in the insulating part in the mantle;
• deriving the vector field which vanishes on every null flux line, i.e. the toroidal part counterbalances the poloidal contribution;