In these graphics, the five dashed lines represent the phase curve expected for a phase-locked atmosphere-free CoRoT-7b with an albedo of 0.3 in the five channels from 0.8 μm (blue) to 3.5 μm (red). The solid lines represent different situations with a grey atmosphere. The relative flux is plotted as a function of the phase, and the zero phase reference is defined as the primary transit position. The parameters for the atmosphere are: top left: P = 100 mb, κ = 1.5 × 10^-5; top right: P = 1b, κ = 1.5 × 10^-5; bottom left: P = 100 mb, κ = 1.5 × 10^-3; bottom right: P = 1b, κ = 1.5 × 10^-3. The IR flux from the cold regions is strongly correlated to the pressure, due to the heat transportation by the atmosphere. The opacity plays a role on the flux from the warmer part of the surface: as the atmosphere becomes more opaque, the substellar region becomes warmer; and the thermal flux is higher when these regions are in front of the observer (around phase 180).