Cyclones brewing further south

CYCLONES are heading further south and increasing in strength, which could have implications for cities like Townsville, a leading climate scientist has discovered.

The phenomenon is called the “poleward shift” which describes the trend of cyclones forming further south towards the Earth’s poles.

The paper “Recent poleward shift of tropical cyclone formation linked to Hadley cell expansion” published in Nature Climate Change, was based on an analysis of where cyclones form.

Co- author Kevin Walsh, a Professor of Meteorology at the University of Melbourne, said the results showed more cyclones were forming in regions further from the equator.

He said the evidence was consistent with predictions about the impacts of climate change, which suggested an expansion of the tropics in the future.

Mr Walsh said other studies indicated the intensity of cyclones was likely to increase because of climate change.

He said further research was needed to find out how the southward trend of cyclones would impact cities in the Coral Sea like Townsville.

“We need to do some more in- depth statistical analysis to find out the implications,” Mr Walsh said.

The findings could mean more cyclones would affect people living on the edges of the tropics, the research found.

The bulk of Australia’s population lives in the southeast coastline of Australia and they could be in the firing line if the trend continues.

Mr Walsh said trends in the data were consistent with big circulation changes in the atmosphere which could imply an expansion of the tropics.

“We haven’t said this trend is definitely due to climate change,” he said. He’s expecting to focus his research into that area next.

In a previous paper Mr Walsh said climate change was likely to lead to fewer tropical cyclones around the world because warm air formed at the ocean surface would not rise as fast. But those that do form will have increased power.

Tropical cyclones are among the most catastrophic of high- impact weather events.