According to the Alfred Wegener Institute for Polar and Marine Research in Germany, these clouds composed of frozen nitric acid and sulphuric acid form when temperatures in the stratosphere at an altitude of about 20 km fall below –78 degrees Celsius. This is currently the case in vast sections of the Arctic. Although these clouds are of natural origin, they have become a portent of imminent ozone loss due to human activity.

Spring Ozone Hole in Arctic

ICTMN Staff
3/25/11

An ozone hole is developing over the Arctic this spring, and although it’ll cause some increased UV ray exposure, that’s only temporary, European scientists announced in March.

The ozone thins every spring, but this year’s shrinkage seems especially severe, although it won’t last, researchers at the Alfred Wegener Institute for Polar and Marine Research in Germany said in a March 14 statement.

“Our measurements show that at the relevant altitudes about half of the ozone that was present above the Arctic has been destroyed over the past weeks,” said institute researcher Markus Rex in the statement. “Since the conditions leading to this unusually rapid ozone depletion continue to prevail, we expect further depletion to occur.”

Low temperatures in the ozone layer above the Arctic sparked the ozone depletion, the news site Science20.com reported.

The temperature drop turns anthropogenic chlorofluorocarbons (CFCs) into “aggressive, ozone-destroying substances,” the press release said. Scientists have long linked ozone loss to climate change, especially about 12 miles up where the ozone layer is coldest. Now, winters at that altitude are getting colder, leading to larger ozone losses.

“The current winter is a continuation of this development, which may indeed be connected to global warming,” said Rex in the institute’s statement.

“Increasing greenhouse gas concentrations retain the earth’s thermal radiation at lower layers of the atmosphere, thus heating up these layers. Less of the heat radiation reaches the stratosphere, intensifying the cooling effect there,” he said. “However, the complicated details of the interactions between the ozone layer and climate change haven’t been completely understood yet and are the subject of current research projects.”

The research was part of a 3.5-million-euro program involving 16 institutions from eight European countries all working to better understand the Arctic ozone layer.

The news wasn’t all bad, however. The ozone layer is expected to recover eventually thanks to the 1987 Montreal Protocol on Substances That Deplete the Ozone Layer, the international treaty in which countries agreed to phase out the production of substances suspected of eating away at the ozone layer.

“By virtue of the long-term effect of the Montreal Protocol, significant ozone destruction will no longer occur during the second half of this century,” Rex said. He added that CFCs released before the treaty will take decades to vanish.

“Don’t panic,” headlined its story. “In the long term the ozone layer will recover thanks to extensive environmental policy measures enacted decades ago for its protection. This winter's likely record-breaking ozone loss does not alter this expectation.”

It does mean, however, that extra sunscreen will be needed as the air holding the ozone floats around to the lower latitudes, as it is wont to do during springtime, Rex said.

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