Secrets of ice bubbles
Scientists on mission New clues to climate
AUSTRALIAN and US scientists are embarking on a mission to Antarctica to investigate a mystery molecule, which may be key to future climate change modelling.
The Australian Antarctic Program summer season begins this week with the Aurora Australis to depart Hobart tomorrow.
One of the key projects this season will be a world-first project to discover how much a natural molecule called hydroxyl has cleaned the air of harmful trace gases since preindustrial times.
CSIRO atmospheric scientist Dr David Etheridge will lead the groundbreaking study and said researchers would drill ice cores to depths of 250m to measure pre-industrial atmospheric levels of hydroxyl, which had never been done before.
“Hydroxyl is a naturally occurring, highly reactive molecule that plays an important role in the atmosphere as a ‘natural air purifier’, by destroying greenhouse gases like methane and industrial chemicals that deplete ozone,” Dr Etheridge said yesterday.
“But we don't understand how much has been removed by hydroxyl.
“To better predict future climate and levels of ozone in the stratosphere we need to know how these components of the atmosphere are removed.”
To accomplish the mission, the team will travel more than 100km from Australia’s Casey research station to Law Dome and build a temporary labora- tory on the ice sheet for three months.
There they will melt hundreds of kilograms of ice, which will produce about 30 litres of air in a delicate and time-sensitive operation.
“As soon as the ice comes to the surface we have to extract the air from it, which is enclosed in the bubbles of that ice,” he said.
“We have to measure that very, very quickly otherwise it starts to get altered by contamination of the surface.”
Dr Etheridge said the extracted air from the ice would then be collected in containers to be sent to Australia and the United States for analysis.
“Those measurements will go into chemical and physical models of the atmosphere, which will tell us about the removal process and that can that be used in climate models,” he said.
Dr Etheridge said Law Dome was the ideal spot for the project because the site was the best place on Earth where snowfall trapped air quickly and preserved it at depth for centuries.
More than 500 people will travel south during the next few months aboard the icebreaker Aurora Australis or on flights from Hobart for multiple projects.
Australia’s Wilkins Aerodrome will be closed for three months to undertake engineering works on the 3.5 kilometre blue ice runway near Casey Station.