Indian Ocean plays profound role in driving southern Australian drought

Canberra, Feb 5 (ANI): In a new research, scientists have found that the Indian Ocean plays a profound role in driving the southern Australian drought.

According to a report in ABC News, the researchers, from the Climate Change Research Centre at the University of New South Wales, discovered that Australia's severe drought is being driven by temperature fluctuations in the Indian Ocean.

"We have found the Indian Ocean plays a profound role in driving the southern Australian drought," said Dr Caroline Ummenhofer of the Climate Change Research Centre at the University of New South Wales.

"We really hope this will improve forecasting of rainfall in that area," she added.

Traditionally, scientists have linked drought in Australia with El Nino - a climate pattern resulting from temperature fluctuations in the Pacific Ocean.

The reverse of El Nino - or La Nina is thought to be responsible for bringing drought-breaking rains to Australia.

But, despite numerous La Nina events, over the past 15 years, southern Australia has been virtually starved of rainfall, raising questions over the role of the Pacific Ocean climate pattern.

"El Nino and La Nina cycles cannot explain the cause," said Ummenhofer.

For their research, Ummenofer and colleagues investigated the role of a climate pattern called the Indian Ocean Dipole (IOD).

In its negative phase, the IOD is characterised by cool water to the west of Australia and warm water to the north, leading to winds that bring warm moist, rain-bearing air to the continent.

In the positive phase, water temperatures are reversed and less moisture travels to Australia.

Looking back over the last 100 years of data, Ummenhofer and colleagues found that all of Australia's long-lasting droughts, including the Federation drought (1885-1902) and the World War II drought (1937-1945), were linked to a low number of negative IOD phases.

According to the researchers, the most recent big dry has seen no negative phases at all.

Ummenhofer said that for the past 15 years, the IOD has been either neutral or positive and in the last few years there were three consecutive positive phases.

"This is something new that in the historical record has never happened before," said Ummenhofer. (ANI)