Three years of measurements from ESA’s Swarm mission have be combined with measurements from Germany’s earlier Champ satellite to produce global climatological maps of Birkeland currents. These currents tend to be weak for a northwards interplanetary field and strong for a southwards field. Importantly, these new results also reveal that the strength of the currents is not the same in both hemispheres. These hemispheric differences may relate to asymmetry in Earth’s main magnetic field.
Read full story: Swarm detects asymmetry