Fri, Jun 03, 2005
NASA Spacecraft Measures Unusual Arctic Ozone Conditions
Despite near-record levels of chemical ozone destruction in the
Arctic this winter,
observations from NASA's Aura spacecraft showed that other
atmospheric processes
restored ozone amounts to near average and stopped high levels of
harmful ultraviolet
radiation from reaching Earth's surface.
Analyses from Aura's Microwave Limb Sounder indicated Arctic
chemical ozone destruction
this past winter peaked at near 50 percent in some regions of the
stratosphere, a region of Earth's atmosphere that begins about 8 to
12 kilometers (5 to 7 miles) above Earth's poles.
This was the second highest level ever recorded, behind the 60
percent level estimated for the 1999-2000 winter. Data from another
instrument on Aura, the Ozone Monitoring
Instrument, found the total amount of ozone over the Arctic this
past March was similar to
other recent years when much less chemical ozone destruction
occurred. So what
tempered the ozone loss? The answer appears to lie in this year's
unusual Arctic
atmospheric conditions.
"This was one of the most unusual Arctic winters ever," said
scientist Dr. Gloria Manney of
NASA's Jet Propulsion Laboratory, Pasadena, CA, who led the
Microwave Limb Sounder
analyses. "Arctic lower stratospheric temperatures were the lowest
on record. But other
conditions like wind patterns and air motions were less conducive
to ozone loss this year."
While the Arctic polar ozone was being chemically destroyed
toward the end of winter,
stratospheric winds shifted and transported ozone-rich air from
Earth's middle latitudes into the Arctic polar region, resulting in
little net change in the total amount of ozone. As a
result, harmful ultraviolet radiation reaching Earth's surface
remained at near-normal levels.
More News
Chaff Thin, narrow metallic reflectors of various lengths and frequency responses, used to reflect radar energy. These reflectors, when dropped from aircraft and allowed to drift d>[...]
“Today, XB-1 took flight in the same hallowed airspace where the Bell X-1 first broke the sound barrier in 1947. I’ve been looking forward to this flight since founding>[...]
“Teaming up with the EAA and Berlin Express for this event in Cincinnati will give warbird fans a unique opportunity to see the aircraft that helped defend freedom and gave t>[...]
Hazardous Weather Information Summary of significant meteorological information (SIGMET/WS), convective significant meteorological information (convective SIGMET/WST), urgent pilot>[...]
Aero Linx: The Nebraska Aeronautics Commission The Nebraska Aeronautics Commission was created by the 1935 Legislature to oversee the development of aviation in the state. The Comm>[...]