Professor Will Cantrell of the Michigan Technological University is supported by the Analytical and Surface Chemistry Program and the Physical Meteorology Program to investigate the molecular-scale mechanisms responsible for the nucleation of ice by particulates. Two classes of foreign substances are to be employed (organic films and insoluble solid surfaces) as a way of interrogating the relative roles of strain accommodation and crystalline defects in the nucleation process. The proposed experiments are designed to probe assumptions of classical nucleation theory such as the role played by the critical embrio, the effect on nucleation of the substrate morphology and the role of structured water molecules in the interfacial region. Infrared spectroscopy will be used in the form of attenuated total reflectance or a variant, attenuated internal reflection, spectroscopy. Graduate and undergraduate students will be educated this interdisciplinary research area involving chemistry, physics and atmospheric science.
Ice formation on or within aerosol particles remains as one of the most poorly understood phenomena in the atmosphere. An improved understanding will allow better predictions of precipitation and the effects of changes in atmospheric aerosols on clouds and climate. This long-standing problem will require careful experimentation coupled with advanced theory to adequately address it.
