Core flow modelling from satellite-derived 'Virtual Observatories'

The last decade has seen a significant improvement in the capability to observe the global field at high spatial resolution using data from satellite missions including CHAMP, Oersted and SAC-C. These data complement the existing record of ground-based observatories, which have continuous temporal coverage at a single point. We wish to exploit these new data to model the secular variation (SV) globally and improve the flow models that have been constructed to date. Using the approach developed by Mandea and Olsen (2006) we create a set of 648 evenly distributed ‘Virtual Observatories’ (VO), at 400km above the Earth’s surface, encompassing satellite measurements from the CHAMP satellite over five years (2001-2005). We invert the SV calculated at each VO to infer flow along the core-mantle boundary. Direct comparison of the SV generated by the flow model to the SV at individual VO can be made.