Satellite Geomagnetism

Satellite measurements today provide global information on the Earth's magnetic field and its time changes, allowing us to study dynamical processes and physical properties of our planet's core, mantle, crust, oceans and upper atmosphere.

In collaboration with Nils Olsen, Lars Tøffner-Clausen (DTU Space), Nicolas Gillet (IsTerre, Grenoble) and Terry Sabaka (NASA), I work with data from the Swarm, CHAMP, Ørsted, and SAC-C satellites, as well as from ground observatories, to construct models of the near-Earth magnetic field.  It is an exciting time in geomagnetism as the three Swarm satellites gradually descend towards the Earth, carrying out the most detailed ever survey of the geomagnetic field.

Visualization of the Swarm satellite trio. Altitude: 450-500km (Credit: ESA)

 Finlay, C.C., Olsen, N., Kotsiaros, S., Gillet, N. and Tøffner-Clausen, L. (2016)  Recent geomagnetic secular variation from Swarm and ground observatories as estimated in the CHAOS-6 geomagnetic field model, Earth Planets Space, Vol 68, 112. doi: 10.1186/s40623-016-0486-1

Sabaka, T.J., Toeffner-Clausen, L., Olsen, N. and Finlay, C.C. (2018) A comprehensive model of Earth’s magnetic field determined from 4 years of Swarm satellite observations, Earth, Planets, Space, Vol 70, 130,

Gillet, N., Barrois, O., and Finlay, C.C. (2015) Stochastic forecasting of the geomagnetic field from the COV-OBS.x1 geomagnetic field model, and candidate models for IGRF-12,Earth, Planets and Space, Vol 67:71  doi:10.1186/s40623-015-0225-z

Olsen, N., Hulot, G., Lesur, V., Finlay, C.C., Beggan, C., Chulliat, A., Sabaka, T.J., Floberghagen, R., Friis-Christensen, E., Haagmans, R., Kotsiaros, S., Luehr, H., Toeffner-Clausen, L., Vigneron, P., (2015) The Swarm Initial Field Model for the 2014 geomagnetic field, Geophysical Research Letters, 42, doi:10.1002/2014GL062659.

  • An important issue of societal importance is to better characterize and understand the weak field South Atlantic Anomaly (see map of field intensity, contours in units of microTesla, from 2018 below), where many upsets of satellite electronics occur (blue dots).

The origin and future evolution of the South Atlantic Anomaly are the subject of the CoreSat project, an ERC consolidator grant for which I am PI.
26 FEBRUARY 2024