Sep 28, 2016

Shift in westerly winds leading to climate impacts is human-induced

Antarctica
Australia
by
Phys.org
Photo: Gizmodo
Photo: Gizmodo

A shortage of data on the weather in Antarctica is hampering efforts to understand climate change in the region, according to new research.

The study, led by Dr Julie Jones from the University of Sheffield's Department of Geography, has revealed that limited data on Antarctica's climate is making it difficult for researchers to disentangle changes caused by human activity from natural climate fluctuations.[1]

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It is only with the advent of regular satellite observations in 1979 that measurement of surface climate over the Antarctic and the surrounding Southern Ocean became possible.

To gain a longer view of recent changes, Dr Jones and her international team of scientists used a compilation of climate records from natural archives, such as ice cores from the Antarctic ice sheet, which give indications of how the region's climate has changed over the last 200 years. They also studied how these recent changes compared to those in experiments with climate models.

They confirmed that human-induced changes have caused the belt of prevailing westerly winds over the Southern Ocean to shift towards Antarctica.

The research concludes that for other changes, such as regional warming and sea ice changes, the observations over the satellite-era since 1979 are not yet long enough for the signal of human-induced climate change to be clearly separated from the strong natural variability in the region

Understanding Antarctic climate change is important not only because of the potential sea level rise locked up in the vast Antarctic ice sheet, but also the shift in the westerly winds has moved rainfall away from southern Australia. In combination with increasing temperatures (this year is set to be the country's hottest year on record) this has had profound impacts on Australian communities and ecosystems