Swarm SCARF Dedicated Lithospheric Field Inversion chain

Abstract

The forthcoming Swarm satellite mission is a constellation of three satellites dedicated to the study of the geomagnetic field. The orbital characteristics of the mission, which includes a pair of satellites flying side by side, has prompted new efforts in data processing and modeling. A consortium of several research institutions has been selected by the European Space Agency (ESA) to provide a number of Level-2 data products which will be made available to the scientific community. Within this framework, specific tools have been tailor-made to better recover the lithospheric magnetic field contribution. These tools take advantage of gradient properties measured by the lower pair of Swarm satellites and rely on a regional modeling scheme designed to better detect signatures of small spatial scales. We report on a processing chain specifically designed for the Swarm mission. Using an End-to-End simulation, we show that the tools developed are operational. The chain generates a model that meets the primary scientific objectives of the Swarm mission. We also discuss refinements that could also be implemented during the Swarm operational phase to further improve lithospheric field models and reach unprecedented spatial resolution.

The Swarm Satellite Constellation Application and Research Facility (SCARF) and Swarm data products

“…Similar to the core field products, model version MLI SHA 2C is derived in the CI chain, while model MLI SHA 2D is determined using the Revised Spherical Harmonic Cap method, as described in Thébault et al (2013). The minimum, resp.…”

Use of along-track magnetic field differences in lithospheric field modelling

“…There have been several studies investigating the use of magnetic field gradient data within well understood synthetic simulations. Thébault et al (2013) have documented the advantages of using east-west field gradients in a regional modelling scheme in order to better detect small scale lithospheric field signatures. Sabaka et al (2013) show how, within their comprehensive modelling framework co-estimating a large number of sources, sums and differences of satellite data can be used to aid both small scale lithospheric field retrieval and source separation.…”

Swarm SCARF Dedicated Ionospheric Field Inversion chain

“…Three main sources are considered: the core, the lithosphere and the electrical currents in the magnetosphere. By default, SCARF dedicated (Hamilton, 2013;Rother et al, 2013;Thébault et al, 2013) and/or comprehensive models are used to remove contributions from these sources. If needed, non-SCARF, auxiliary models will be considered during the exploitation phase to improve the quality of the final model.…”