Convenor: Nicolas Gillet (France)
Co-Convenors: Vincent Lesur (France), Arnaud  Chulliat (USA)

The almost two decades of continuous geomagnetic measurements from low orbiting satellites provide us with unprecedented constraints on the rate of change of the Earth's dynamo field. They complement more than 150 years of accurate observatory records. New prospects about interannual to decadal core dynamics are thus made possible, with implications concerning for instance the debated stratified layer at the top of the core (and the heat budget), the propagation of waves that carry information on the core state, or the nonlinear rotating magneto-hydrodynamics.

We solicit contributions on topics such as the modeling of rapid field changes and their link to magnetic observations, core flow motions, geomagnetic data assimilation, or the forward simulations of transient core processes.