Results of three numerical simulations with with T₀ = 2 × 10⁶ K, Δ = 0.5 Mm, and ρ_b0 = 10⁻¹⁰ kg m⁻³ (red), ρ_b0 = 5 × 10⁻¹⁰ kg m⁻³ (green), and ρ_b0 = 10 × 10⁻¹⁰ kg m⁻³ (blue). (a) Density as a function of height at a given time. (b) Velocity as a function of height at a given time. A dashed vertical black line is plotted at z = z₀ − C_st giving the position of the front of the compression wave. The dashed vertical red, green, and blue lines give the position of the maximum density. Animations of these figures can be found online.