The Project

General

The Swarm mission is designed to measure the magnetic signals that stem from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere. This will lead to better understanding of the processes that drive Earth’s dynamo, which currently appears to be weakening. By studying the complexities of Earth’s protective shield, Swarm will provide a clear insight into processes occurring inside the planet. Along with measurements of conditions in the upper atmosphere, a better knowledge of the near-Earth environment and the Sun’s influence on the planet can be realised. In particular, Swarm aims at providing a unique view inside Earth to study:

  • Core dynamics, geodynamo processes and core-mantle interaction;
  • Magnetism of the lithosphere and its geological context;
  • 3D electrical conductivity related to mantle composition;
  • The weak electric currents related to ocean flow.

We study at feasibility level the use of magnetic gradient grids derived from Swarm data for lithospheric modelling. In a first step, magnetic field gradients will be derived from the data of the three Swarm satellites. Next, these gradients will be used to compute magnetic gradient grids at 450 km altitude for one example region, North-West Europe. With sensitivity analysis it will then be studied what the added benefit of these gradient grids is for lithospheric modelling. North-West Europe is chosen because it is a tectonic interesting region including well defined lithospheric scale magnetic sources, and because a wealth of aeromagnetic data is available, which will allow to validate our results.

Sketch showing the benefit of GOCE and Swarm gradient data for lithospheric modelling.Aeromagnetic map of the example region.

The work and the institutes

Roughly the work can be divided in four parts: derivation of along track gradients, computation of magnetic gradient grids, geophysical modelling, interpretation and validation, scientific outreach.

  • DTU Space will derive from the Swarm magnetic vector data along track gradients for Swarm A, B and C and cross track gradients between Swarm A and C
  • DGFI-TUM will use these gradients to produce grids of magnetic gradients at mean satellite altitude (~450 km)
  • CAU Kiel is responsible for the geophysical modelling and interpretation, as well as the Scientific Roadmap
  • NGU is responsible for the compilation of airborne data and the validation