May 10th 06, 12:28 AM
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Alan Buis (818) 354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
David Terraso (404) 385-2966
Georgia Institute of Technology, Atlanta, Ga.
News Release: 2006-074 May 9, 2006
Tibet Provides Passage for Chemicals to Reach the Stratosphere
NASA and university researchers have found that thunderstorms
over Tibet provide a main pathway for water vapor and chemicals
to travel from the lower atmosphere, where human activity
directly affects atmospheric composition, into the stratosphere,
where the protective ozone layer resides.
Learning how water vapor reaches the stratosphere can help improve
climate prediction models. Similarly, understanding the pathways
that ozone-depleting chemicals can take to reach the stratosphere
is essential for understanding future threats to the ozone layer,
which shields Earth from the sun's harmful ultraviolet rays.
Researchers from the Georgia Institute of Technology, Atlanta;
NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and the
University of Edinburgh, Scotland, performed their analysis using
data from the Microwave Limb Sounder instrument on NASA's Aura
spacecraft, combined with data from NASA's Aqua and Tropical
Rainfall Measuring Missions.
The team collected more than 1,000 measurements of high
concentrations of water vapor in the stratosphere over the
Tibetan Plateau and the Asian monsoon region. The measurements
were collected during August 2004 and August 2005, during the
height of monsoon season. Through the use of wind data and NASA
atmospheric models, they found the water vapor originated over
Tibet, just north of the Himalayan mountain range.
The team also found that even though more thunderstorms occurred
over India, the storms over Tibet transported nearly three times
more water vapor into the lower stratosphere than the more
frequent thunderstorms that occur over India.
"This study shows that thunderstorms over Tibet are mainly
responsible for the large amount of water vapor entering the
stratosphere," said Dr. Rong Fu, associate professor in Georgia
Tech's School of Earth and Atmospheric Sciences, who led the
study. "The rainfall may not be as frequent over Tibet as over
the Indian monsoon area, but because Tibet is at a much higher
elevation than India, the storms over Tibet are strong and
penetrate very high, and send water vapor right into the
stratosphere."
The study also found that the same pathway is responsible for
transporting carbon monoxide, an indicator of air pollution,
into the upper atmosphere.
"There's almost no carbon monoxide production in Tibet, so it's
widely believed that carbon monoxide is transported to the
tropopause over Southeast Asia and the Indian subcontinent," Fu
said. The tropopause divides the lower atmosphere from the
stratosphere, and is located at an altitude of about 18 kilometers
(11 miles) above Earth over the tropics and Tibet.
Fu added, "Our study finds thunderstorms over Tibet transport
as much carbon monoxide to the lower stratosphere as do those
over India. When long-lived pollutants are transported out of
the lower atmosphere, they can move rapidly. Pollutants from Asia,
for example, can wind up on the other side of the world."
The findings are published in the Proceedings of the National
Academy of Sciences.
Aura, Aqua and the Tropical Rainfall Measuring Mission are part
of the NASA-centered international Earth Observing System, and
are managed by NASA's Goddard Space Flight Center, Greenbelt, Md.
Aura's Microwave Limb Sounder was built by JPL.
For more information on the Microwave Limb Sounder and Aura,
visit:
http://mls.jpl.nasa.gov and http://aura.gsfc.nasa.gov .
For information on Aqua and the Tropical Rainfall Measuring
Mission, visit:
http://aqua.nasa.gov/ and http://trmm.gsfc.nasa.gov/ .
JPL is managed for NASA by the California Institute of
Technology.
-end-
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Alan Buis (818) 354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
David Terraso (404) 385-2966
Georgia Institute of Technology, Atlanta, Ga.
News Release: 2006-074 May 9, 2006
Tibet Provides Passage for Chemicals to Reach the Stratosphere
NASA and university researchers have found that thunderstorms
over Tibet provide a main pathway for water vapor and chemicals
to travel from the lower atmosphere, where human activity
directly affects atmospheric composition, into the stratosphere,
where the protective ozone layer resides.
Learning how water vapor reaches the stratosphere can help improve
climate prediction models. Similarly, understanding the pathways
that ozone-depleting chemicals can take to reach the stratosphere
is essential for understanding future threats to the ozone layer,
which shields Earth from the sun's harmful ultraviolet rays.
Researchers from the Georgia Institute of Technology, Atlanta;
NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and the
University of Edinburgh, Scotland, performed their analysis using
data from the Microwave Limb Sounder instrument on NASA's Aura
spacecraft, combined with data from NASA's Aqua and Tropical
Rainfall Measuring Missions.
The team collected more than 1,000 measurements of high
concentrations of water vapor in the stratosphere over the
Tibetan Plateau and the Asian monsoon region. The measurements
were collected during August 2004 and August 2005, during the
height of monsoon season. Through the use of wind data and NASA
atmospheric models, they found the water vapor originated over
Tibet, just north of the Himalayan mountain range.
The team also found that even though more thunderstorms occurred
over India, the storms over Tibet transported nearly three times
more water vapor into the lower stratosphere than the more
frequent thunderstorms that occur over India.
"This study shows that thunderstorms over Tibet are mainly
responsible for the large amount of water vapor entering the
stratosphere," said Dr. Rong Fu, associate professor in Georgia
Tech's School of Earth and Atmospheric Sciences, who led the
study. "The rainfall may not be as frequent over Tibet as over
the Indian monsoon area, but because Tibet is at a much higher
elevation than India, the storms over Tibet are strong and
penetrate very high, and send water vapor right into the
stratosphere."
The study also found that the same pathway is responsible for
transporting carbon monoxide, an indicator of air pollution,
into the upper atmosphere.
"There's almost no carbon monoxide production in Tibet, so it's
widely believed that carbon monoxide is transported to the
tropopause over Southeast Asia and the Indian subcontinent," Fu
said. The tropopause divides the lower atmosphere from the
stratosphere, and is located at an altitude of about 18 kilometers
(11 miles) above Earth over the tropics and Tibet.
Fu added, "Our study finds thunderstorms over Tibet transport
as much carbon monoxide to the lower stratosphere as do those
over India. When long-lived pollutants are transported out of
the lower atmosphere, they can move rapidly. Pollutants from Asia,
for example, can wind up on the other side of the world."
The findings are published in the Proceedings of the National
Academy of Sciences.
Aura, Aqua and the Tropical Rainfall Measuring Mission are part
of the NASA-centered international Earth Observing System, and
are managed by NASA's Goddard Space Flight Center, Greenbelt, Md.
Aura's Microwave Limb Sounder was built by JPL.
For more information on the Microwave Limb Sounder and Aura,
visit:
http://mls.jpl.nasa.gov and http://aura.gsfc.nasa.gov .
For information on Aqua and the Tropical Rainfall Measuring
Mission, visit:
http://aqua.nasa.gov/ and http://trmm.gsfc.nasa.gov/ .
JPL is managed for NASA by the California Institute of
Technology.
-end-