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History of Cloud Seeding

Origins of Cloud Seeding

Discovery of Cloud Seeding (1946)

The proof of concept of cloud seeding was discovered by Vincent J Schaefer, Bernard Vonnegut, and Irving Langmuir (seen to the right) in 1946. Schaefer and Langmuir were researching icing on aircraft at the General Electric Company’s research laboratory after World War 2.

By investigating the production of particles of various sizes and their behavior in the atmosphere, they discovered the proof on concept that particles could be seeded into clouds to produce ice. They were able to nucleate (seed) a laboratory made cloud in a freezer with dry ice to create snow. Vonnegut later discovered that silver iodide was an even more affective seeding agent, which was a breakthrough discovery for cloud seeding.

Image 1. Image of Vincent J. Schaefer, Bernard Vonnegut, and Irving Langmuir discovering the concept of cloud seeding in 1946 (image by the GE News Bureau)

First Cloud Seeding Experiment (1947)

The first cloud seeding experiment called “Project Cirrus” happened in 1947. A modified B17 bomber dropped dry ice (solid carbon dioxide) into a stratus cumulus cloud. This experiment proved successful when they saw a “Racetrack” dissipation pattern in the clouds (which does not naturally occur in clouds). This was evidence that ice was produced, and that cloud physics and precipitation could be altered. 

These methods were used in the Vietnam War for generating smokescreens by the military. These principles and experiments were the steppingstones to further understanding weather modification by seeding clouds.

References: The role of induced entrainment in past stratiform cloud seeding experiments (Walcek)

Image 2. Image  of the first cloud seeding experiment showing the racetrack pattern proving cloud seeding works (image by the U.S. Army Signal Corps)

History of Cloud Seeding in Idaho

Cloud seeding operations have been occurring in various parts of Idaho since the early 1950’s. These earlier programs were locally sponsored, manually operated ground seeding projects. More consistent operations began in the late 1990’s with the development of the High Country Resource Conservation & Development’s (HCRCD) East Idaho program, operated by Let it Snow (LIS). This program is currently the longest operational program in the State of Idaho. Idaho Power Company (IPC), in response to a shareholder questions, also began investigating cloud seeding in the late 1990’s to support its hydropower generation. IPC began its first operational project in the Payette River Basin in 2003. Prior to IPC’s cloud seeding efforts, the Boise Board of Control contracted with the National Association of Water Companies (NAWC) for the operations of manual ground generators in the Boise River Basin for over a decade.

Table 1. Table of all historical cloud seeding operations in Idaho

History of the Collaborative Cloud Seeding Program

The Idaho Water Resource Board (IWRB) began investigating cloud seeding in 2008 as a water management strategy to support the Eastern Snake Plain Aquifer (ESPA) Comprehensive Aquifer Management Plan (CAMP). As a part of the CAMP, IPC proposed to develop and operate a 5-year pilot project in the Upper Snake River Basin, and if successful, the State and local water users would come to the table to discuss the long-term operation of a program. This project was developed and was expanded to include the Boise and Wood basins at the request of the water users. 

In 2017, IPC approached the IWRB about partnering in the build out of the program. The IWRB initially contributed funds for capital expenses and later provided funding for the development of modeling and computing technologies to support cloud seeding operations, planning and design of projects, and ultimately the estimation of benefits. The Collaborative Cloud Seeding Program was then created, which is a collaborative program between the IWRB, IPC, HCRCD, and local water users in the Upper Snake, Boise, and Wood River basins. A full timeline of the Collaborative Cloud Seeding Program is shown below.

Figure 1. Timeline of the Collaborative Cloud Seeding Program

  • 2008 | ESPA CAMP implementation of a 5-year pilot project in the Upper Snake Basin; Operations and Funding by IPC 
  • 2013-2014 | Water users in the Wood and Boise River Basins approached IPC about the potential for developing new projects
  • 2015 | IWRB provided cost share with IPC and began participation in program funding with capital for new infrastructure
  • 2016 | IWRB began contributing towards program operations and modeling (1/3 total program cost)
  • 2017 | IWRB Partnered with IPC for development of Weather Research and Forecasting Cloud Seeding model (WRF-WxMod)
  • 2017 | SNOWIE study field campaign in the Payette River Basin
  • 2019 |Program reached existing build-out (3 aircraft, 57 remote generators, network of weather instrumentation) and initiated cloud seeding analysis
  • 2019 | IWRB directed staff to conduct an analysis of cloud seeding (CS) operations (CS Analysis)
  • 2020 | Initial results of the CS Analysis; IWRB directed staff to conduct a more detailed investigation, utilizing sophisticated modeling tools
  • 2021 | Legislature passed House Bill 266 (HB266) on cloud seeding
    Directed the IWRB to:
    • Continue cloud seeding analysis
    • Complete an assessment of cloud seeding opportunities statewide
    • Authorize cloud seeding programs in State
    • Provides authority to sponsor or develop local or statewide cloud seeding programs
  • 2021 | IWRB directed staff to conduct: a more detailed cloud seeding analysis; a statewide cloud seeding assessment; and a feasibility and design study of the Bear River Basin
  • 2021 | Bear River Basin Pilot Aircraft project
  • 2022 | Statewide assessment results using silver iodide (AgI) presented to IWRB CS Committee
  • 2022 | IWRB directed staff to conduct feasibility and design study of the Lemhi River B
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