ESA: Antarctic ozone hole is smaller

DE BILT, Netherlands, Oct. 8 (UPI) -- The European Space Agency determined the ozone hole over Antarctica has shrunk 30 percent as compared with last year's record size.

The ESA said measurements made by its Envisat satellite show this year’s ozone loss peaked at 27.7 million tons, compared with the 2006 record ozone loss of 40 million tons.

Scientists believe this year’s smaller hole is due to natural variations in temperature and atmospheric dynamics and isn't indicative of a long-term trend.

"Although the hole is somewhat smaller than usual, we cannot conclude from this that the ozone layer is recovering already," said Ronald van der A, a senior project scientist at the Royal Dutch Meteorological Institute. "This year's ozone hole was less centered on the South Pole as in other years, which allowed it to mix with warmer air, reducing the growth of the hole because ozone is depleted at temperatures less than minus 78 degrees Celsius."

The ozone hole, first recognized in 1985, typically persists until November or December, when the winds surrounding the South Pole weaken, and ozone-poor air inside the vortex is mixed with ozone-rich air outside it, the ESA said.