Pressure scale height (H_P) profiles as function of shell radius for set of 3D snapshots. Vertical lines indicate the radial geometrical distances from the stellar center (averaged over a given snapshot and over time) corresponding to the tomographic masks C1–C5, along with the locations corresponding to τ_Ross = 1 (denoted as R_*) and τ₀ = 20 000. The bands are standard deviations of the averages over time.