Reactions on tropospheric condensed matter

Reactions on/in condensed media play important roles in the chemistry of the troposphere. These reactions can be classified as heterogeneous reactions, those occurring on the surfaces of solids, and multiphase reactions, those occurring inside a liquid droplet. A few general considerations in the treatment of heterogeneous and multiphase reactions are discussed. Based on the knowledge and experience obtained from the study of stratospheric heterogeneous and multiphase reactions, possible characteristics of such processes in the troposphere are described and illustrated using a few examples. It is noted that the variety of condensed media in the troposphere makes this a rich field for investigation. The possible importance of reduction reactions in the oxidizing atmosphere is examined. The reactions on soot are highlighted and the potential importance of reactions on organic aerosol and other media is discussed. Finally, the outlook for progress in this area is very briefly discussed.