Selected RAIRS spectra of CO deposited on water-dominated ice after the ice was annealed to temperature T_ann and then cooled to 20 K. T_ann is 20, 40, 60, 80, 100, and 120 K from top to bottom. The three columns are for (1) 200 ML of pure H₂O ices, (2) mixed ices of 200 ML H₂O and 20 ML NH₃, and (3) mixed ices of 200 ML H₂O and 40 ML CO₂. The insets of the figure refer to the amount of deposited CO.