SCIENCE : Antarctic Ozone Layer Climbing
From Times Wire Services
WASHINGTON —
The layer of protective ozone over the South Pole is easing back toward normal after nearly reaching a record low this year, the National Oceanic and Atmospheric Administration reported today.
The filling of the so-called ozone hole is occurring late this year because of persistent winds circling Antarctica, which have prevented air over that continent from mixing with the atmosphere in other regions, scientists say.
Ozone levels over Antarctica finally climbed to 220 dobson units Dec. 6 and to 270 units by Dec. 10, according to measurements made by instruments sent aloft in balloons.
Ozone over the South Pole reached a low of 130 dobson units in early October, only marginally above the record low measured in 1987.
