Collaborative Research: SNOWIE: Seeded and Natural Orographic Wintertime clouds: the Idaho Experiment

University Of Wyoming, Laramie WY

Investigators

Abstract

This award is for an observational and modeling campaign that will address the impact of cloud seeding on orographic winter precipitation. There is a lack of concrete evidence that cloud seeding has the intended impact of increasing precipitation, yet several states in the western US have conducted seeding operations over many years. With advanced observational tools and computer modeling the researchers involved in this project believe that they can build the scientific foundation for weather modification as a tool for precipitation enhancement. The researchers will heavily instrument the area around the Idaho Power Company's seeding operations in the Payette Mountains to collect data on the effectiveness of these activities. This award represents a public/private partnership that has the potential to improve the viability of the cloud seeding operations and has implications for the water-hungry populations in the western US. Multiple graduate and undergraduate students would be involved in the field work and data analysis, ensuring the development of the next generation of atmospheric scientists. The Seeded and Natural Orographic Wintertime clouds: the Idaho Experiment (SNOWIE) field campaign will take place in early 2017 in the Payette Mountains of Idaho. The main observational assets that will be used are the University of Wyoming King Air research aircraft with in-situ and remote sensing instruments, the CSWR Doppler on Wheels mobile radars, and a host of ground-based remote sensing and in-situ precipitation sensors. The overall goals of the project are to understanding the natural dynamical and microphysical processes by which precipitation forms and evolves within orographic winter storms and to determine the physical processes by which cloud seeding with silver iodide (AgI), either from ground generators or aircraft, impacts the amount and spatial distribution of snow falling across a river basin. The core scientific objective of the proposal are to: 1) Evaluate the role of mesoscale and microscale dynamics and of the underlying terrain in the formation, growth, and fallout of natural ice crystals in winter storms through observations, 2) Investigate how the natural snow growth process is altered as a result of airborne AgI seeding through both observations and model simulations, and 3) Evaluate the effects of ground seeding on snowfall amount and distribution.