Field line helicity morphology for the snapshot at t = 120 of the non-eruptive emergence simulation (top panel), the snapshot at t = 110 of the eruptive emergence simulation (middle panel), and the snapshot at t = 920 of the jet formation simulation (bottom panel). The left plots show representative field lines coloured by the value of their RMFLH overplotted on the photospheric map of B_z. In the top two plots, field lines are drawn from the contours B_z = ±0.3 and the lines at x = ±50, while in the bottom plot from the contour B_z = 5 and the circle of radius r = 3.4 centred on the image. The right plots show the respective 2D maps of RMFLH on the photospheric plane.