Effect of the inner boundary of the 3D GCM models on the mean molecular weight, μ, and the geometric atmosphere extension for the giant gas planet example WASP-43b. Right: based on the 1D thermodynamic profiles from Parmentier et al. Right: based on the 1D thermodynamic profiles from Carone et al. There is a difference of ~0.5 × 10⁸ cm between the day and night geometric extensions, of the same profiles, between the two models.