Stellar envelope specific entropy s_ad from 3D RHD simulations and 1D MLT stellar models. Left: simulations and evolution tracks have the same convective envelope chemical composition, and s_ad has been plotted in a manner similar to Figure 3. The three evolution tracks are 1.1 M_⊙ models evolved to approximately 8.6 Gyr and were constructed with different values of the mixing length parameter, α. Right: variation of s_ad in 1D main-sequence stellar models as a function of α. The stellar models have the same surface conditions, but only one value of α produces a stellar model matching the specific entropy from a 3D simulation (dashed line) with the same surface conditions. Note that this calibration mapping of α into s_ad depends on the choice of the T–τ relation.