Atmospheric structure of the symmetric idealized case, ∇⁺T, assuming an absence of H₂ dissociation. We show the temperature map (top) and the water abundance map (bottom). The temperature gradient goes from 500 to 3500 K. The transmission angle is 10° around the terminator line and has a 2500 K ring at P = 0.13 bar from the surface pressure. From the center outward, the five solid lines are, respectively, the 10⁶, 10³, 1, 10⁻², and 10⁻⁴ Pa pressure levels. The color-coding for the water abundance maps goes from 5 × 10⁻⁴ to 10⁻⁷. The radius of the planet and the atmosphere are shown to scale. The temperature and abundance maps of the ∇⁻ T case are almost the same, except the scale height of the atmosphere is smaller.