Australia is a more important source of dust circulating in the Southern Hemisphere than previously thought, says an Australian scientist.
The comments from Professor Patrick De Deckker of the Australian National University in Canberra, come on the eve of him receiving an Australian Academy of Science award for his contribution to earth sciences.
"Australia is a major supplier of dust in the Southern Hemisphere," says De Deckker, who will receive the 2010 Mawson Medal.
De Deckker and colleagues have been showing how many places in the Southern Hemisphere have been affected by Australia's dust - today, and in the past.
They have been identifying the origin of dust by studying its composition, including isotopes of strontium, neodymium and lead.
"Our work is described as an attempt at fingerprinting dust," says De Deckker.
De Deckker and colleagues combine the dust analysis with chemical analyses of particular landscapes, as well as satellite and meteorological analyses to work out where dust has come from.
Using dust fingerprinting, De Deckker and colleagues have tracking the source of dust in ice cores from Dome C in Antarctica dating back 150,000.
"Our work published earlier this year identified that dust from the Darling River region was transported to central Antarctica over several hundreds of thousands of years," says De Deckker.
"People thought originally that a lot of the dust came from Patagonia."
De Deckker says the study suggests tweaking of models designed to represent past atmospheric circulation in the Southern Hemisphere.
Other studies of dust particles found at Law Dome show lead isotopes that have been traced back to mining operations in Australia, he says.
Sydney dust storm
De Deckker has also studied samples collected from the recent dust storms that hit Canberra and Sydney confirm much of it came from the Lake Eyre region.
The dust travelled as far as New Caledonia and New Zealand.
In the future, De Deckker hopes to use fingerprinting to work out how frequently dust storms have occurred in the past in Australia.
"Before Europeans arrived in Australia, was Australia as dusty as it is today?" he asks.
He says knowing the answer to this question will help us manage the land more sustainably.
De Deckker has also been working with microbiologists and is finding numerous microbes and pollen grains carried in the dust.
"We're quite concerned that some of these microbes could affect human health or environmental health."
So far no pathogens of significance have been identified. But samples of dust from New Zealand have been collected to test for possible fungal pathogens that may be of concern to farmers in that country.
De Deckker says in some parts of the world dust storms lead to an increase in respiratory complaints and outbreaks in coral disease.
"My question is whether it is really the mineral components or the pathogens that are in the dust that are to blame for these problems."