Antarctic ozone hole now as big as North America

(Livescience.com) 

The ozone hole above the Antarctic has reached its maximum extent for the year, revealing a gouge in the protective atmospheric layer that rivals the size of North America, scientists have announced.

Spanning about 9.7 million square miles (25 million square kilometers), the ozone hole over the South Pole reached its maximum annual size on Sept. 14, 2011, coming in as the fifth largest on record. The largest Antarctic ozone hole ever recorded occurred in 2006, at a size of 10.6 million square miles (27.5 million square km), a size documented by NASA's Earth-observing Aura satellite.

The Antarctic ozone hole was first discovered in the late 1970s by the first satellite mission that could measure ozone, a spacecraft called POES and run by the National Oceanic and Atmospheric Administration (NOAA). The hole has continued to grow steadily during the 1980s and 90s, though since early 2000 the growth reportedly leveled off. Even so scientists have seen large variability in its size from year to year.  Read Full