Ice in the environment, from ice particles in clouds, to sea ice and snow at the Earth’s surface, has a profound influence on atmospheric composition and climate. Understanding and quantifying the chemical interactions of ice and snow with trace gases in the atmosphere is a major challenge in atmospheric chemistry. A quantitative, mechanistic understanding of trace gas–ice interactions is critical for predicting the effects of climate change on atmospheric composition, for the interpretation of ice core chemical records, and for modeling atmospheric chemistry. There are significant gaps in our current understanding of air–ice chemical interactions, including uncertainty regarding the microphysical location of species upon uptake, rates and mechanisms of chemical processes taking place in/on ice, the role of interfacial layers at the ice surface, and the role of biological activity.

This special issue is comprised of a series of review articles originating from the 3rd Workshop on Air-Ice Chemical Interactions (AICI), which was held at Columbia University in New York, NY, June 6–8, 2011.