Closing ozone hole may heat up Antarctica - researcher

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The ozone hole over New Zealand is closing, but it may warm up Antarctica which could then affect the West Coast and Canterbury Plains, a university researcher says.

Dr Adrian McDonald, from Canterbury University's Physics and Astronomy department, was commenting after data released by the World Meteorological Organisation showed the ozone layer would recover between the years 2050 and 2100.

However, as a result of the ozone hole closing, Antarctica would probably become warmer, Dr McDonald said.

An international agreement designed to reduce harmful substances such as chlorofluorocarbons (CFCs) has helped reduce the size of the ozone hole. It was believed that if the Montreal Protocol was adhered to, the ozone layer was expected to recover before the next century, Dr McDonald said.

Since the beginning of the 1980s, an ozone hole had developed over Antarctica during the spring, resulting in a decrease in ozone concentration of up to 70 per cent.

Climate change in Antarctica was an important matter to New Zealand because higher temperatures caused ice to melt, resulting in rising sea levels, Dr McDonald said.

"With the ozone recovery, the future of Antarctic climate is less certain, though the complex interactions in the atmosphere associated with climate change makes this region particularly hard to predict.

"The future recovery of the Antarctic ozone hole and increases in greenhouse gases will have significant impacts on the wind circulation in the southern hemisphere.''

Dr McDonald planned to head to Scott Base in November to deploy a set of wirelessly connected weather stations which will retrieve high resolution weather data as part of his Antarctic research.

The ozone layer and climate change played an important part in New Zealand's atmospheric conditions, he said.

"The temperature difference between the poles and the equator controls wind patterns over New Zealand, which could potentially mean increased-rainfall on the West Coast or dryer Canterbury Plains.''

The recovery of the ozone hole should move the winds back towards the equator, Dr McDonald said.

"The increasing ozone hole has until now acted to change the circulation of the Southern Hemisphere so that the strong winds linked to the jet streams (fast wind currents) have moved towards the pole.''