Structure functions (solid) and (dashed) for the case “unified” (top panel), as well as computed along the x-direction (middle panel) and y-direction (bottom panel), i.e., parallel and perpendicular to the upstream flow, for simulations R*_2 at ℓ = 12. Color coding as in Fig. 2. Also indicated are slopes and as obtained by Kritsuk et al. (2007a) from 3D periodic box simulations. Curves are vertically shifted, to start from one common point.