New international research has found a worrying change in the Indian Ocean’s surface temperatures that puts south-east Australia on course for increasingly hot and dry weather conditions.
The work led by the Australian National University (ANU) and the ARC Centre of Excellence for Climate Extremes has a silver lining, helping to improve our understanding of climate variations and the management of risk caused by Indian Ocean variability.
Lead researcher Professor Nerilie Abram said the phenomenon her team studied, known as the Indian Ocean Dipole (IOD), was a big player in the severe drought and record hot temperatures last year.
The new research published in Nature reveals that these historically rare events have become much more frequent and intense during the 20th Century, and this situation is expected to worsen if greenhouse gas emissions continue to rise.
According to Bureau of Meteorology climatologist Dr Andrew Watkins, a very strong positive IOD and a near-record negative Southern Annular Mode resulted in both the warmest and driest December weather on record.
“In January we saw those two drivers return to neutral levels, plus a very late arrival of the northern monsoon which finally brought tropical moisture to the continent,” Dr Watkins said.
“As we often see once the monsoon arrives in the north, some of that tropical moisture was dragged south, leading to some of the good recent rainfall over the country’s east.”
The outlook for autumn weather shows both daytime and overnight temperatures are likely to be above average for most of the country.
In terms of rainfall, Dr Watkins said many areas were showing no strong push towards wetter or drier than average conditions in the coming months. However, parts of southern and south-eastern Australia are showing a slightly increased chance of above average rainfall in the coming three months, particularly in March.
The ACT has already benefited from some welcome rain with five days recording falls this month, as at Monday 9 March.