Mathematical investigation of mass transfer for atmospheric pollutants into a fixed droplet with aqueous chemistry

The objective of this article is to investigate some of the classical parameterizations used for modeling mass transfer between interstitial gas and cloud droplets for aqueous-phase models in Air Pollution Modeling. After an appropriate scaling of the initial model ( a set of two coupled Partial Differential Equations), we apply the singular perturbation theory and some theoretical results of Reaction-Diffusion models with large diffusion coefficients. This justifies the use of classical parameterizations in a large range of parameters. Moreover, we propose a new parameterization of mass transfer, taking into account aqueous-phase diffusion limitations. This parameterization is based on a double-film model and may have an impact for some species, as it is illustrated with a simple box model.