Typical modeled annual evolution of surface pressure obtained with LMD Pluto volatile transport model, assuming permanent deposits of N₂ ice inside Sputnik Planitia and in the depression of mid-northern latitudes, a uniform soil seasonal thermal inertia of 800 J s^−1∕2 m⁻² K⁻¹, an emissivity ɛ_N2 = 0.8 and albedo range A_N2 = 0.72–0.73 for N₂ ice, chosen to yield a surface pressure near 10–11 μbar in July 2015. The black dots with error bars show the surface pressure (p_surf) inferred from stellar occultation pressure measurements (see Table 2). The curve in magenta corresponds to a similar simulation but assuming a permanent N₂ ice reservoir in the south hemisphere between 52.5 and 67.5° S, which leads to a pressure peak in 1990.