Parameterizations for homogeneous and heterogeneous ice nucleation

Ice nucleation is an important process in numerous environmental systems such as atmospheric aerosol droplets or biological tissues. Two different approaches are widely used in the atmospheric community: the lambda approach and the water-activity-based approach. Freezing experiments using the Differential Scanning Calorimeter are performed in inorganic, organic and inorganic/organic mixtures using different ice nuclei (Arizona Test Dust, silicium oxide particles, Pseudomonas syringae bacteria, oxalic acid, long chain alcohols and silver iodide). The results are presented in several recent publications:

• Zobrist et al., Oxalic acid as a heterogeneous ice nucleus in the upper troposphere and its indirect aerosol effect, Atmos. Chem. Phys., 6, 3115–3129, 2006 pdf of the article,
• Zobrist et al. Heterogeneous ice nucleation in aqueous solutions: the role of water activity, J. Phys. Chem. A, 112, 3965-3975, 2008. article online,
• Zobrist et al., Do atmospheric aerosols form glasses?, ACP, 8, 5221-5244, 2008. pdf of the article
• Koop and Zobrist, Parameterizations for ice nucleation in biological and atmospheric systems, PCCP, DOI:10.1039/B914289D, 2009.