2013ApJ...773L..17T

We examine timing noise in both magnetars and regular pulsars, and find that there exists a component of the timing noise (σ_TN) with strong magnetic field dependence (σ_TN ∼ B_o²ΩT^3/2) above B_o∼ 10^12.5 G. The dependence of the timing noise floor on the magnetic field is also reflected in the smallest observable glitch size. We find that magnetospheric torque variation cannot explain this component of timing noise. We calculate the moment of inertia of the magnetic field outside of a neutron star and show that this timing noise component may be due to variation of this moment of inertia, and could be evidence of rapid global magnetospheric variability.