Water Resources Research Act Program

Details for Project ID 2018WY95B

Numerical Simulations of the Impact of Cloud Seeding in the Wind River Range on Precipiation, Snowpack, and Streamflow

Institute: Wyoming
Year Established: 2018 Start Date: 2018-03-01 End Date: 2020-02-28
Total Federal Funds: $11,997 Total Non-Federal Funds: $126,497

Principal Investigators: Bart Geerts

Project Summary: To examine the feasibility of cloud seeding to enhance precipitation and runoff in Wyoming, the State of Wyoming commissioned the Wyoming Weather Modification Pilot Project (WWMPP, 2007-14). The focus of this project was a randomized statistical experiment (RSE) examining the impact of ground-based silver iodide (AgI) seeding on snowfall in the Medicine Bow and Sierra Madre mountains. The Wind River Range (WRR) was seeded as well, by a network of 10 AgI generators, whenever the meteorological conditions were suitable, but no RSE was conducted. A final WWMPP report (Rasmussen 2014) and a host of published observational and numerical modelling studies, supported by the UW Water Research Program and the National Science Foundation, indicate that glaciogenic seeding of orographic clouds in the Medicine Bow and Sierra Madre can increase precipitation, although the amounts and optimal seeding conditions remain rather uncertain. Less is known about the impact of cloud seeding over the WRR on snowpack and streamflow. The execution of another properly designed RSE would cost millions of dollars and require many years of data collection. Instead, we propose to numerically simulate the impact of cloud seeding during the past decade in the WRR, using a state-of-the-science seeding module developed by the National Center for Atmospheric Research (NCAR) (Xue et al. 2013a, b). This module is integrated into the Weather Research and Forecasting (WRF), a widely used atmospheric model, and a detailed land surface scheme (Noah Multi-Physics). This approach will enable us to realistically assess the impacts of seeding on snowpack in the WRR and streamflow in the Green River in less time, for less money. This project, a collaboration with Drs. Rasmussen and Xue at NCAR, will build on previous state-funded modelling work completed for the WRR.