Pacific Ocean wind patterns responsible for global climate instability: Aussie research

Unusual wind patterns in the Pacific Ocean are responsible for global climate fluctuations over the past 2, 000 years, a new Australian research has found.

The research by Canberra's Australian National University (ANU) found that the El Niño and La Niña "wind oscillations" have been responsible for global warming and droughts for thousands of years.

Researchers are optimistic that the new data, published on Friday in the British scientific journal "Nature Communications", will assist scientists in building accurate long-term future climate models.

Alena Kimbrough, who led the ANU's participation in the study, said that the main focus of the study was on climate changes over hundreds of years.

"Our study looked at the long, long term changes. It's really important because what we found is these century-scale changes in the Pacific can have a significant impact on global temperatures and rainfall," Kimbrough told Xinhua in an interview on Friday.

"Once we started to piece things together I was quite surprised at how important it really was."

The oscillations are a natural event that occur in the tropical Pacific usually one to eight years apart.

The El Niño Southern Oscillation (ENSO) is a result of east-west winds in the region abating for a short time period, causing water temperatures to rise, whereas La Niña is the opposite effect.

The team was able to reverse engineer rainfall statistics from centuries ago by measuring trace elements and stable isotopes stored in stalagmites on the Indonesian island of Flores.

"What we were able to do was develop our records of rainfall over Floros then compare our record to already published work ... to establish how the whole rainfall system was changing," Kimbrough said.

One extreme example of the impact the El Niño oscillation can have on a climate is the medieval climate anomaly during which the northern hemisphere experienced widespread severe drought between the years 950 and 1,250.

"Our records showed that the northern hemisphere was dry during that period and records showed the tropics were very wet in that time," said Kimbrough.

"So by looking at these patterns you can establish what the tropical pacific was doing at that time." Endit