Dipolar Spherical Elementary Current Systems (DSECS) toolbox



The purpose of this project is to create a user-friendly version of a previously developed analysis method for estimating ionospheric currents at low and middle latitudes.

Magnetic measurements by LEO (Low Earth Orbit) satellites provide important information about the ionospheric current system, about their connection to the magnetosphere via field-aligned currents (FAC) at high latitudes, and about the connection between the current systems in the northern and southern hemispheres via inter-hemispheric FAC at middle and low latitudes.

The Spherical Elementary Current System (SECS) method was applied to the data provided by the pair of parallel-flying Swarm-A and Swarm-C satellites by Amm et al. (2015, https://dx.doi.org/10.1002/2014JA020154). The unique configuration of the two satellites makes it possible to derive 2-dimensional latitude-longitude maps of the currents around the satellites’ paths. Since its introduction, the Swarm/SECS analysis method has been employed in several studies.

The 'traditional' SECS method can be used only at polar and auroral latitudes, as it assumes radially flowing field-aligned currents. However, an alternative dipole approach, called DSECS (dipolar elementary current systems), accounts for magnetic signature due to currents that follow dipole field geometry and is thus applicable to middle and low latitudes. This DSECS method was demonstrated by Vanhamäki et al (2020, https://dx.doi.org/10.1186/s40623-020-01284-1).

In this project, based on the recommendations of the Swarm DISC Advisory Board (DAB), ESA has decided to support a streamlining of the existing DSECS toolbox and method in order to improve performance and open-up the method to a wider user community.

Project duration: February 2022 – October 2022. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-026.