Hemispheric asymmetries in Spherical Elementary Current-derived currents observed from North America, Greenland and Antarctica

We employ ground magnetometers in North America, Greenland, and Antarctica and use the Spherical Elementary Current (SEC) technique in order to investigate the currents flowing between January 2015 and December 2016. We convert the measurements into altitude-adjusted corrected geomagnetic (AACGM) coordinates to allow us to investigate the hemispheric asymmetries between conjugate points. There are data gaps during the Southern Hemisphere winters due to difficulties of making ground-based observations at these times. We subset the measurements to control for the different spatial extents of the data in either hemisphere, and then average spatially and temporally so that we can compute the asymmetry. We contextualise the asymmetry in terms of AMPERE, Swarm, and DMSP-observed asymmetries, and discuss what this implies for the ionospheric conductance in either hemisphere.