Profiles (y-averaged) of the ion temperature anisotropy (solid lines); the marginal stability condition of Eq. (11) (dotted lines) at time Ω_cit = 8 for shocks with different plasma β and M_s = 3 and θ_Bn = 75° (runs A2–A6, panel a); different sonic Mach numbers and β = 20 and θ_Bn = 75° (runs C1–C6, panel b); and a range of obliquity angles for M_s = 3 and β = 10 (runs A3 and B1–B7, panel c). The x coordinate was normalized to the ion gyroradius r_g(M_s, β) of each model.