Large ozone hole over Antarctica likely
21 August 2003
Scientists are predicting a large ozone hole over much of Antarctica this spring.
Ozone is a protective layer that lies around Earth rather like a veil and shields us from the ultraviolet-B (UVB) radiation of the sun's rays.
Parliamentary Secretary for the Antarctic Dr Sharman Stone said that a larger ozone hole meant that people were likely to be at greater risk of sunburn and should take precautions.
"Our scientists are telling us that the trend in atmospheric readings above Antarctica are similar to those observed in 2000, when the ozone hole was of record size and about three times the size of Australia," Dr Stone said.
A joint project by Australian Antarctic Division (AAD) and Bureau of Meteorology scientists collecting data at Australia's Davis station in Antarctica have found colder than usual atmospheric temperatures present, and these contribute to a hole in the ozone.
Dr Stone said that news of the likelihood of a large hole over Antarctica this year was disappointing.
"This is the legacy of ozone depletion over many years and reinforces just how long it can take to repair the damage.
"However, recent news that repair is underway further up in the stratosphere is confirmation that measures adopted internationally in 1987 are working.
"We have known for some time that synthetic gases, such as chlorofluorocarbons (CFCs), cause the stratospheric changes that lead to a hole in the ozone layer and Australia was at the forefront in phasing out their use and production," Dr Stone said.
"Chlorofluorocarbons were commonly used as propellants in spray cans and refrigerants."
AAD atmospheric scientist, Dr Andrew Klekociuk, said that the project by the AAD and Bureau of Meteorology was providing the first in-situ measurements of stratospheric ozone by Australian scientists in Antarctica.
"At Davis station we saw the first signs of cooling of the lower stratosphere – 15 to 25 kms above Antarctica - some six weeks earlier than usual.
"The current trends are similar to those in 2000. The ozone hole then was of record size and covered an area about three times that of Australia. This is in contrast to the situation in 2002 when unusually warm conditions produced the smallest ozone hole since 1988," Dr Klekociuk said.
Dr Stone said that It was clear that Australian science in Antarctica was helping to piece together the big picture of global climate and ozone depletion.
Dr Stone added that the Federal Government's recently-introduced Ozone Protection and Synthetic Greenhouse Gas Legislation Amendment Bill would ensure that Australia continued to build on its already well-established commitment to controlling the use of substances that have detrimental impacts on the global atmosphere.
"For example, the importation of refrigeration and air-conditioning equipment containing ozone-depleting substances, such as hydrochlorofluorocarbon, will be better controlled."
"The Bureau of Meteorology forecasts the Ultraviolet (UV) Index graph daily for each state and territory.
"This index gives an indication of the degree of sun protection required each day," Sharman Stone said.