Left panel: profile of Γ₁ between the BCZ and 0.95 R_⊙ for the solar models in Table 1. Right panel: entropy proxy profile, P/ρ^Γ₁, as a function of normalised radius for the solar models of Table 1. The reference evolutionary models (‘Ref’) show a significant spread in entropy proxy plateau in the CZ that is corrected in the seismic models (‘Seismic’) by the seismic reconstruction procedure.