Geomagnetic data analysis

The Swarm mission of ESA is today central to the efforts carried by the geomagnetic community. It will allow a better description of external magnetic fields, and thus open a window towards the dynamics in the core at interannual (to monthly ?) periods. This evolution occurs at the same time a new generation of geodynamo simulations arises. It is timely to combine the above two aspects through data assimilation studies. Because we only have access to a limited amount of geophysical constraints (the field at the core surface), this requires to develop reduced models able to reproduce the rapid dynamics in the core. This is the rationale under the development of magnetic quasi-geostrophic equations, or of stochastic models anchored to geodynamo statistics.

Our efforts are supported by the Centre National d’Etudes Spatiales (CNES). In this context, we propose several products to the community:

– the geomagnetic data assimilation tool pygeodyn;

– the web platform webgeodyn for core surface flow and magnetic field visualization;

– the magnetic field model COV-OBS that covers eras of observatory and satellites magnetic records (1840-2020, coll. DTU Space, Copenhagen).