Antarctica 'stealing' Australia's rain: study

Antarctica is "stealing" Australia 's rainfall, explaining why the former is not warming as much as other continents and why southern Australia is recording more droughts, the Australian National University (ANU) reported on Monday.

Researchers in Australia have found rising levels of carbon dioxide in the atmosphere are strengthening the stormy Southern Ocean winds. These would normally deliver rain to southern Australia but are instead pushing further south towards Antarctica.

"With greenhouse warming, Antarctica is actually stealing more of Australia's rainfall," said Dr Nerilie Abram, lead researcher from the ANU Research School of Earth Sciences.

"As the westerly winds are getting tighter they're actually trapping more of the cold air over Antarctica," she said.

"As greenhouse gases continue to rise we'll get fewer storms chased up into Australia."

Until this study, published in Nature Climate Change, Antarctic climate observations were available only from the middle of last century.

But by analyzing ice cores from Antarctica and data from tree rings and lakes in South America, Dr Abram and her colleagues were able to extend the history of the westerly winds over the past millennium.

"The Southern Ocean winds are now stronger than at any other time in the past 1,000 years," she said.

"The strengthening of these winds has been particularly prominent over the past 70 years, and by combining our observations with climate models we can clearly link this to rising greenhouse gas levels."

Antarctica had bucked the trend, Abram said, with every other continent warming, and the Arctic warming fastest of anywhere on earth.

The study findings come on the back of a Bureau of Meteorology assessment that Australia remains on course for its first El Nino effect in more than four years.

These weather events typically bring a drier winter and spring to southern Australia and active bushfire seasons in the summer.

The effect is caused by warm sub-seawater temperatures, as much as 6 degrees Celsius above normal, spreading eastwards in the tropical Pacific and heralding the formation of an El Nino, the Bureau of Meteorology said.