Can heterogeneous core–mantle electromagnetic coupling control geomagnetic reversals?

An analytical model is developed for the electromagnetic torques exerted on the mantle by the poloidal magnetic field of the core interacting with a laterally heterogeneous conducting layer at the base of the mantle. Torques due to changes in both orientation and intensity of a dipolar poloidal field are included. Contrary to earlier suggestions, our calculations predict that the trajectory of the magnetic pole during a polarity reversal is not strongly affected by heterogeneity in mantle electrical conductivity.