Space agency reports biggest-ever ozone hole over Antarctic dpa German Press Agency

Published: Friday October 20, 2006 Washington- The US space agency NASA announced Thursday that atmospheric scientists in recent weeks observed the largest hole in the ozone layer ever recorded over the Southern Hemisphere. Gaps in the ozone layer, which blocks much of the sun's harmful ultraviolet rays, expand and contract over time but are blamed primarily on human activity that releases chlorine and bromine gases that destroy zone. Depleted ozone patches are especially exposed at Earth's poles.



"From September 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles," Paul Newman, atmospheric scientist at NASA's Goddard Space Flight Centre, said in a statement.



The ozone hole reported over the Antarctic was larger than the surface area of North America.



An instrument on NASA's Aura satellite measured total ozone from Earth's surface to the upper atmosphere. Other US government scientists used instruments mounted on balloons to make direct measurements of ozone over the South Pole.



Measurements taken in early October showed even lower concentrations of ozone, particularly at an altitude of 13 to 21 kilometres, showing that the ozone layer was "virtually gone in this layer of the atmosphere," said David Hofmann, director of the US National Oceanic and Atmospheric Administration's Earth System Research Laboratory.



"The depleted layer has an unusual vertical extent this year, so it appears that the 2006 ozone hole will go down as a record-setter."



© 2006 dpa German Press Agency



