Study shows extreme contrast in ozone losses at North, South Poles

CHICAGO (AFP) - A new study shows just how dramatic the ozone loss in the Antarctic has been over the past 20 years compared to the same phenomenon in the Arctic.

The study found "massive" and "widespread" localized ozone depletion in the heart of Antartica's ozone hole region, beginning in the late 1970s, but becoming more pronounced in the 1980s and 90s.

The US government scientists who conducted the study said that there was an almost complete absence of ozone in certain atmospheric air samples taken after 1980, compared to earlier decades. In contrast, the ozone losses in the Arctic were sporadic, and even the greatest losses did not begin to approach the regular losses in the northern hemisphere, the researchers said.

"Typically the Arctic loss is dramatically less than the Antarctic loss," said Robert Portmann, an atmospheric scientist with the National Oceanic and Atmospheric Administration in Boulder, Colorado.