NASA - 2012 Antarctic Ozone Hole Second Smallest in 20 Years
WASHINGTON -- The average area covered by the Antarctic ozone hole this year was the second smallest in the last 20 years, according to data from NASA and National Oceanic and Atmospheric Administration (NOAA) satellites. Scientists attribute the change to warmer temperatures in the Antarctic lower stratosphere..."The ozone hole mainly is caused by chlorine from human-produced chemicals, and these chlorine levels are still sizable in the Antarctic stratosphere," said NASA atmospheric scientist Paul Newman of NASA's Goddard Space Flight Center in Greenbelt, Md. "Natural fluctuations in weather patterns resulted in warmer stratospheric temperatures this year. These temperatures led to a smaller ozone hole."October 17, 2012: Antarctica could follow same path as Arctic sea ice melt
That still leaves the question as to why Antarctic sea ice is increasing when local and global temperatures are warming. Scientists will not know the answers until more research is done. But they think it is partly the result of wind and ocean movements. NSIDC director Mark Serreze also attributes a role to the hole in the ozone layer above Antarctica. He explains that because of this, the stratosphere above Antarctica is very cold. ''Ozone in the stratosphere absorbs UV [ultra violet] light, and less absorption [by] ozone makes the stratosphere really cold,'' he says. This cold air descends to the surface, keeping the sea ice extensive.
No comments:
Post a Comment