Earth’s core as modelled in the numerical geodynamo simulation as part of research into geomagnetic jerks and rapid hydromagnetic waves published as the cover story in Nature Geosciences, May 2018. The magnetic field lines (orange) are stretched, twisted and folded by the turbulent convection producing shear of electrically conducting fluid (red and blue). Hydromagnetic waves are triggered when the shear is misaligned with field lines, and propagate along these lines to the surface of the core where they can focus and cause geomagnetic jerks.
Read full story: Swarm helps explain Earth's magnetic jerks