| Droughts and flooding rains to intensify|
|A new breed of El Nino is on the rise causing more intense monsoons over northern Australia, says a climate scientist.|
The research, published in today's edition of the journal Nature, isn't good news for farmers either with more intense droughts predicted for the Top End.
El Nino events traditionally bring warm waters to the eastern Pacific Ocean, write the authors.
But recent studies have shown that these El Ninos are decreasing in frequency and a new type, called El Nino-Modoki, are becoming more common.
El Nino-Modokis are generally characterised by warmer waters in the central Pacific Ocean, and cooler waters in the western and eastern regions of the ocean.
Dr Andrea Taschetto, of the University of New South Wales (UNSW), says the researchers, based in South Korea and the US, used climate models prepared by the Intergovernmental Panel on Climate Change to predict the effects El Nino-Modokis would have in the future.
They believe El Nino-Modokis could increase as much as five times due to global warming.
Taschetto says wind patterns associated with Modoki interact with seasonal winds in northern Australia to bring more intense monsoons during the wet season.
"So if Modokis increase their frequency in the next few decades, that certainly will affect northern Australia," says Professor Matthew England, also of UNSW.
But Modokis won't just bring more intense monsoons, England says more frequent Modoki patterns could have significant impacts on the farming sector in northern Australia outside the wet season.
"In 2002 we saw some of the highest reductions in rainfall that we've ever experienced in some parts of Australia - and that was an El Nino-Modoki year," he says.
England says while Modokis will increase the severity of the northern monsoons, their impact on southern Australia's climate is less certain.
Professor Neville Nicholls, of Monash Universityin Melbourne, says it should not be assumed that the long drought over southern Australia is due to changes in the El Nino.
"Work by several groups in Australia has identified that this drought is related to an intensification of the band of high pressure over southern Australia," he says.
He says this intensification may have little to do with long-term changes in the El Nino.
Research published earlier this year suggests Australia's severe drought is being driven by temperature fluctuations in the Indian Ocean - known as the Indian Ocean Dipole.