Days of future drought By Justin D. Hunt
The Albury/Wodonga region may once again face water restrictions thanks to a major drought bringing the El Nino effect in. While a recent drought report released by the Australian Government Bureau of Meteorology has shown the Riverina Region has come out of its Millennium drought that lasted from late 1996 to mid 2010, which may be set to change.
At the time of writing the Bureau had yet to announce a report confirming or denying El Nino’s effect, experts say that it’s all but certain, with sea surface temperatures in the central and eastern Pacific recording anomalies of more than 1 degree.
“You can see a warming in the eastern Pacific, which looks to be a classic [El Nino] event,” said Dr Agus Santoso, an El Nino modeller at the University of NSW’s Climate Change Research centre in an interview with The Sydney Morning Herald. “It’s quite rare, this is [going to be] an interesting one”
While El Nino has always been expected, it’s the early start to the process that has climate scientists concerned the planet may be on the way to a particularly strong event. “If it peaks in winter then dies off it’s interesting,” Dr Santoso said. “But if it keeps going up and peaks in summer, that could potentially be a big El Nino.”
Doctor Cai Wenju, a leading climate modeller at the CSIRO, said experts were predicting a strong El Nino a year ago but sustained westerly winds failed to eventuate. “Last year at this time, we didn’t see the [westerly] winds.”
As a result, the atmosphere did not “couple” with, or reinforce, the warming trends in the oceans. “This time, we see the strong westerly winds all along the equator.” Dr Cai went on to say.
While previous good rainfall years will soften the blow, towns in the Murray-Darling Basin will feel the biggest impact, with Broken Hill’s storage levels down to about 4 per cent.
Eastern Australian rainfall is typically below average, particularly in winter and spring. Having analysed 12 strong El Nino events, the Bureau of Meteorology says that the biggest departures from long term average rains were in most of inland NSW and parts of southern Queensland. Relatively clear skies mean areas already dry may be declared drought hit. Meanwhile with dry soils, evaporation is reduced, making bushfire season worse than usual.