Maps of the dynamical lifetime in generic DNS, as a function of Re and Rm (L_x = 0.7, L_y = 20, L_z = 2). Each row is for a different random initial condition. The second and third maps (from top to bottom) use the same noise realization (see text) but different amplitudes (A = 5 for the second case and A = 2.5 for the third case). The maps on the left are for simulations at mild Re and Rm that can be conducted at moderate numerical resolution (48 × 48 × 72). The maps on the right are for higher Re and Rm, requiring a higher resolution (96 × 96 × 128). The dashed line corresponds to Pm = 1.