SWARM Explorer: Combined use of satellite and airborne magnetic field data to explore lithospheric magnetisation

Magnetic gradient data from the new SWARM satellite mission will provide new high-resolution data for Earth. We intend to combine this data set with conventional airborne magnetic data sets to the study the magnetisation of the lithosphere. We will explor e how magnetic data from different times, and therefore different inducing field, will differ and how we can explore this to estimate the remanent component in lithospheric magnetisation. We plan also to acquire some long aeromagnetic profiles over an are a with assumed high remanence and as the data are acquired during the SWARM mission period, we can use the data as well to validate the satellite data with ground data. This validation will allow us to verify how satellite data can be used to correct for diurnal variations in aeromagnetic surveys, especially for offshore areas where the distance to geomagnetic observatories or base station can be very large. Furthermore, we want to model how induced and remanent magnetisation and the depth of magnetic sou rces affect the field at the different heights and times. This requires the implementation of spherical modelling codes for the magnetic field and its gradients. The lithospheric modelling will be constrained by the petrophysical data base for Fennoscandi a, which will allow making realistic estimates of the geometry of the near-surface geology.