Seeds of doubt: Cloud seeding has been controversial, but a new 45-year study seems to show it can cause a modest improvement in rainfall.
Credit: iStockphoto
Despite the caveats, other experts are excited by the results.
“At long last there is scientific backup for the [cloud seeding] hypothesis that has been suggested over the years,” commented Roger Stone, director of the Australian Centre for Sustainable Catchments at the University of Southern Queensland in Toowoomba.
However, while the study is a breakthrough, he noted that cloud seeding does not work in all locations and specific techniques have to be developed for each region.
“For example, in Queensland the conditions are highly different. It has to be the right time and exactly the right cloud for it to work,” he said. “The key is to get a very good weather radar.”
Let it snow
Paul Johnson, a spokesperson from Snowy Hydro, who are conducting similar experiments to artificial induce snowfall in Victoria's Snowy Mountains, said the results were promising. "It's another indicator that supports our preliminary data and backs up what the experts said in the beginning. That we would see an increase in snow."
Because of the unusual nature of the Tasmanian clouds, additional studies may be needed to determine if the cloud seeding really was the cause of the increase in rainfall.
"Unfortunately, very little cloud physics research has been associated with the cloud seeding experiment in Tasmania, so that we are at the full mercy of the statistics," commented Daniel Rosenfeld, a climatologist from Hebrew University of Jerusalem in Israel.
"Clouds do not distinguish between the impacts of aerosols based on our intentions when we disperse them," he said. "Therefore, understanding cloud seeding and impacts of air pollution is inseparable."
Pollution effects
Rosenfeld has previously worked on computer models of weather systems to understand the effects of cloud manipulation, and he admitted it is difficult to directly link cloud seeding with weather patterns.
"It has been much easier to detect impacts of air pollution, because we pollute the clouds at a much grander scale than we seed them intentionally," he said.
Siems said the new study may have wider implications. He hopes the research highlights the importance of weather radar technology and will pave the way for a better understanding of weather patterns.
"The more we understand precipitation and the better climate models we have, the closer we will be to understanding droughts," he said, a significant problem in Australia.
cloud seeding
however much i enjoy and understand this information we need more, as in how do you make the rain and what (if you were to show) would you use as an example? think about the little things when you prove your information. thank you
sincerely yours
jessica