North Pole’s Ozone Layer Monitored in Light of Antarctic Hole
ANCHORAGE, Alaska (AP) _ Scientists in the Arctic Circle have been closely monitoring the ozone layer at the North Pole since experts discovered a breach in the Earth’s protective layer at the South Pole.
Thus far, the Geophysical Monitoring for Climatic Change station at Point Barrow, the only such testing site in the Northern Hemisphere, has not found evidence of a gap, officials said.
Such a hole, caused by pollution, would allow higher levels of solar radiation to reach Earth.
″If a decrease in the ozone layer can happen at the South Pole in Antarctica, it can also happen at the North Pole, if conditions are right,″ said Bernard Mendonca, deputy director of the National Oceanic and Atmospheric Administration’s Environmental Research Laboratory in Boulder, Colo.
The lab funds the Alaska station, as well as three others worldwide.
Scientists first discovered the opening in the ozone layer, 10 to 15 miles above the South Pole, two years ago.
Satellite observations have confirmed a progressive deterioration in the protective layer, Mendonca said. ″About 40 percent of the ozone above the south polar cap is gone,″ he said.
The deterioration is believed to be caused by circular winds sweeping up high-altitude pollutants, trapping them in the stratosphere for long periods.
″The most common (pollutants) are Freon gases used as propellants in aerosol cans,″ Mendonca said.
The ozone layer protects the Earth’s surface from harmful ultraviolet solar radiation emitted by the sun. Ultraviolet rays cause some forms of skin cancer and can cause damage to plant and animal life, scientists say.
The Point Barrow station is also measuring carbon dioxide levels in the northern reaches of the hemisphere. Carbon dioxide is a waste product of fossil fuels used in automobiles, heating and power generation.
″It can accumulate in the atmosphere and prevent radiant heat from the sun that has reached the Earth’s surface from escaping back into space,″ Mendonca said. ″That causes what we’ve come to know as the greenhouse effect.″
The Barrow region shows the highest carbon dioxide levels in the world. ″That only happens in the winter, and we don’t know why,″ he said.
Since 1974, scientists have predicted a gradual depletion of stratospheric ozone as a result of increased atmospheric pollution.
Officials say the Barrow station was largely responsible for the discovery in 1953 of arctic haze, that transient mass of pollution which hovers above the arctic in winter months.
Mendonca said the haze is of particular interest in the Northern Hemisphere because of its mobility.
″If the arctic haze were to get high enough and into the stratosphere where the ozone layer exists, pollutants in the atmosphere may have a chance to destroy the ozone layer like it has in Antarctica,″ he said.
So far, he said, scientists have not noticed that phenomenon at the North Pole.