A Gravitational Tug-of-War Inside Earth: Rotation and the Decadal Wobble in Day Length
A new modeling study covered by Nature News finds that millisecond-scale decadal variations in Earth's length of day are best matched by a combination in which gravitational torque dominates and is counterbalanced by electromagnetic and mechanical torques, with a key input coming from a 2023 Nature Geoscience paper that used repeating seismic waves to infer a recent pause in inner-core differential rotation within an approximately seven-decade oscillation.