Hydrated complexes: Relevance to atmospheric chemistry and climate

Intermolecular interactions in molecular clusters can significantly alter the optical properties and reaction dynamics of the constituent monomers. As a result, both atmospheric chemistry and climate may be affected. We review here the spectroscopy and photochemistry of molecular hydrates and point to their possible relevance to the Earth's atmosphere. Data needed to model the atmospheric effects of hydrates includes calculation of both their abundance and their absorption cross-section. We discuss these issues and examine the potential spectroscopic effects of hydrates in the atmosphere, as well as the fundamental work needed to quantify better the magnitude of these effects.