We first analyze the structure of the solvation shell of NO - 3 obtained from the deprotonation of nitric acid and from ammonium nitrate at the air-ice interface and in water. Before comparing the solvation structure of nitrate in water and at the air-ice interface, we observe that at the ice surface, NO - 3 is fully solvated in the QLL, as opposed to larger hydrophobic pollutants that float on top of the QLL (Figure ). However, when NO - 3 forms a complex with NH + 4 , the ion pair is located at the tail of the density profile. These differences in the QLL embedding lead to different solvation environments for NO - 3 , and influence its molar absorption coefficient, possibly influencing its molar absorption coefficient and photodissociation kinetics.