Wyoming Weather Modification Projects Still Waiting for Results

Mar 26, 2012

Wyoming is host to two of the world’s most comprehensive weather modification studies. The studies are unique due to our geography, but they’re also more comprehensive than past research has been. And the water-hungry world is waiting for results. Irina Zhorov reports. 

IRINA ZHOROV: Cloud seeding is a crazy way to solve our water issues. For one, what scientists are doing is shooting silver iodide into clouds in an attempt to eke out some extra moisture. But also, instead of sitting in a lab or even a test site researchers fly in a very small plane into dangerous storm clouds.

The plane’s pilot is Brett Wadsworth.

BRETT WADSWORTH: The winds are going to be howling up there today…

ZHOROV: The wind you’re listening to is from inside the hangar building. It’s worse outside.

[Take-off ambi]

ZHOROV: The research aircraft is loaded down with remote sensors and atmospheric instrumentation and on this morning it soared just at dawn over the Snowy Range Mountains and towards the Sierra Madres.

The plane is used as part of the Silver Iodide Seeding Cloud Impact Investigation – or ASCII – which piggybacks on the ongoing efforts of the Wyoming Weather Modification Pilot Project. The Pilot project seeks to collect a large pool of data to essentially determine when and how well seeding works.

Barry Lawrence is a project manager with the Water Development office in Cheyenne, which runs the Pilot study.

BARRY LAWRENCE: It's not the first, but it definitely is bringing the latest and greatest technology, it's trying to document the entire chain of events, from the formation of the ice crystals to fall out and then run off. So we're trying to document that whole chain of events and hydrologic process.

ZHOROV: Lawrence has overseen the legislatively funded Pilot project for the last five years. And lawmakers just extended it for another two years.

LAWRENCE: It’s all about getting enough of these cases, these four hour events, to come up with that statistical significance.

ZHOROV: Right now there are 118 completed cases of seeding and observing, and Lawrence says they’re looking to have another 50 to 60.

The companion project, the ASCII campaign, is run by a consortium of institutions, including University of Wyoming. It is funded by the National Science Foundation. Bart Geerts runs the project and he says it’s been decades since the NSF funded a weather modification study.

BART GEERTS: I believe there are two reasons for why the National Science Foundation decided to fund this. One is that the instruments that are being used now are far superior to instruments that were used a few decades ago. The other reason probably is that the observations now can be used to validate models of far higher resolution and accuracy than existed back in the 1980s and earlier. 

ZHOROV: Geerts explains that ASCII focuses on processes rather than statistics. What they’re trying to do is understand, in great detail, exactly what happens when seeding material is shot into the clouds. 

Together the two projects are being closely watched the world over. First, these projects are unique in that they focus on winter snowpack enhancement, whereas most of the limited research is happening in more temperate zones. But also because even in places like China, where a lot of cloud seeding is done, there is rarely a significant evaluation component to the practice. This leaves researchers with a bit of a blank when people ask just how effective weather modification is.

This is Dan Breed.

DAN BREED: One of the difficulties in weather modification is that when it was first discovered…it was a very exciting experiment and result but it was taken and run with…it was oversold, is one way to put it, or hyped as the panacea for lots of things.

ZHOROV: Breed is a project scientist at the National Center for Atmospheric Research, which is responsible for doing an independent analysis of the data from the Pilot project. He says numbers are important, but they won’t quite prove or disprove anything.

BREED: If someone asks you, does cloud seeding work? Well, that’s not the right question because clearly it does work in some instances and clearly it doesn’t work in other instances. So you need to say, when does cloud seeding work?

ZHOROV: Breed says that modeling, which is a part of the Pilot project’s work, will help to predict when it works and whether it’s worth doing. Then it becomes a question for water managers.

BREED: Well, then it becomes is a few percent worth it? You look at it in terms of acre feet and actually when you do the cost-benefit analysis, it’s pretty cheap water. So even impacts on stream flow as little as 1 or 2% can  make or break or at least have an impact on storage and utility of water that you wouldn’t have had if you hadn’t done any seeding.

ZHOROV: The ASCII scientists still have not started analyzing their data. Lawrence, from the Water Development Office, was hesitant to reveal too many details about the Pilot project since the study is still ongoing.

LAWRENCE: I can tell you that it's trending positive, we have preliminary numbers.

ZHOROV: That might be all we get for now.

For Wyoming Public Radio, I’m Irina Zhorov.