Nelson/Abstract 9703123 The goals of this project are: 1) to discover the physical causes of snow crystal shape by the measurement of key surface parameters used in crystal growth models, and 2) to improve instruction in physical meteorology by introducing experiments into a required undergraduate/graduate lecture course. A new method of controlled ice crystal growth that was successfully developed to measure critical supersaturations for vapor growth on both basal and prism faces of ice above -16 degrees Celsius. The improvements are need to extend the range of conditions measured, but will also increase control over the crystal environment. This method can be used for related fundamental and applied studies in cloud physics with little or no modification. Five to six research quality experiments will be added to our existing physical meteorology course for seniors and first-year graduate students. Each student would perform approximately 3 experiments per semester. Experiments would be 2 hours long or more and treated like a homework assignment. The experiments will be chosen to complement the lectures and faculty research projects and therefore can be used for additional undergraduate research with the appropriate professor when the equipment is available. For example; a simplified version of our ice crystal growth apparatus could be used both for a laboratory exercise to illustrate crystal growth and the different snow crystal shapes, and for an undergraduate research project to measure the effect of electric fields on the critical supersaturations for vapor growth of ice.
