Sowing snow seeds
by Rodney Magazinovic
The
Snowy Mountains without snow? Unthinkable – but in recent years, the
decreasing level of snowfall, particularly in the environmentally
sensitive Kosciuszko National Park, is one reason why Snowy Hydro
Limited is undertaking a six-year cloud seeding research project to
enhance snowfalls in this region.
Cloud seeding is by no means a new technology – it has been successfully used to augment water supply systems around the world for the past 50 years.
The process involves increasing the concentration of ice crystals in
clouds that contain sufficient
below-freezing water droplets, and which
would not naturally precipitate as snow.
This process of creating additional ice crystals is referred to as ice nucleation by cloud seeding.
As the ice crystals grow in size, they form snowflakes and fall to the ground as snow.
Silver iodide is the most commonly used seeding agent because its structure is very similar to naturally occurring ice nuclei. It is seeded into the clouds via ground-based generators.
UniSA graduate John Denholm is the project director of the Snowy Precipitation Enhancement Research Project (SPERP) and he says the project, begun in 2004, was a large undertaking that required a big commitment by Snowy Hydro, the co-operation of numerous government departments and a bill in parliament for it to go ahead.
“It was a significant effort to bring together all the people and infrastructure in a very short time,” Denholm said.
Denholm graduated from UniSA in 1996 with a degree in computer and information science. He also completed a technician's certificate at SAIT (an antecedent institution of UniSA).
His role has seen him coordinate the SPERP design and operation while overseeing a team of 45 people during the winter snow season.
The research project could produce up to 10 per cent more snow per season in the targeted areas, resulting in an average increase in water yield of 70 gigalitres – the equivalent of 70,000 Olympic swimming pools.
As well as producing snowfall that is essential to maintain the ecological values of Kosciuszko National Park, once the snow melts in spring, extra water is available for the generation of renewable hydro electricity, as well as providing more water for downstream users.
“The final outcomes of SPERP will be a determination of the economical viability of cloud seeding while ensuring further benefits are delivered and there is no significant environmental impact,” Denholm said.
While it is too early to say if the project will be successful in meeting these aims, the first year’s results have been promising, with increases of up to 25 per cent in many of the snow samples that had a seeding signature.