Hinode's Observational Result on the Saturation of Magnetic Helicity Injected into the Solar Atmosphere and Its Relation to the Occurrence of a Solar Flare

Views of how emerging flux might develop into a flare, with the usual deceptive 2D representation of what is inherently a 3D problem. The idea represented here is reasonable: the field struggles to inject an already-formed flux rope into the corona, fighting against the force of gravity on the entrained plasma. The paper discusses this in terms of an apparent saturation of helicity injection, making use of the excellent Hinode observations of the vector magnetic field. As the flux rope rises, its axis finally appears and then some different geometry happens - an interaction with pre-existing open field (left) or all by itself (right).