Comparison of the flow structure in two simulations with very disparate heating parameters. The left panel shows simulation sr30 (Θ = 10^-3, L = 10¹). The right panel shows simulation sr03 (Θ = 10⁰, L = 10⁴). In both cases, the vertical velocity component w, normalised to its maximal absolute value, is plotted on a split logarithmic colour scale. The length of the velocity vectors (arrows) is scaled in a non-linear way to aid visualisation. The spatial coordinates are normalised by the characteristic length scales defined in Sects. 2.3 and 3.