Variation of quenching pressure with the zenith angle, using the zeroth-order approximation (Sect. 3.1). Temperature profiles of all trajectories are color-coded above the quenching pressures. Minimum quenching pressure occurs at theevening terminator, where the atmosphere contributes significantly in the transmission spectra. The effects of disequilibrium chemistry are therefore expected to be less pronounced in the transmission spectra. Variation of quenching pressure is represented with the dashed line.