Evaluation Plan for a Snow Enhancement Experiment in Australia

Abstract

A comprehensive suite of tests is developed to evaluate the Snowy Precipitation Enhancement Research Project, a cloud seeding project in south eastern Australia aimed at increasing snow fall.  The project will use both physical and chemical observations for its primary evaluation. An analysis of historical data shows that there is an 80% chance that more than 100 five-hour experimental units will occur over the five-year duration of the project. Moreover, although there is a significant amount of natural variability in the properties of experimental units, it is appropriate to treat all experimental units as members of the one class of event. A bootstrap analysis of the historical data shows that there is about a 75% chance that a 20% increase in precipitation will be detected at the 10% significance level. On the basis of bootstrap analysis, the primary analysis for the project is taken to be the identification of a positive seeding impact at the 10% significance level in the primary target area, together with snow chemistry results showing at the 5% significance level that ice nuclei have been activated in the primary target area. A number of secondary analyses are identified to support the results of the primary analysis.