Cross sectional area of the gas particles as a function of pressure, with vertical lines denoting the pressure at which the Knudsen number exceeds 1. The solid vertical lines show the pressure limit for the molecular gas, and the dashed lines show the pressure limit for the fully ionised gas. The profiles are shown for all planetary effective temperatures for the sub-stellar, anti-stellar, morning terminator and evening terminator points. All the models have log(g)=3 [cgs] and orbit G5 stars.