Tibet Pathway for Chemicals To Reach Stratosphere

May 10, 2006
Tibet Pathway for Chemicals To Reach Stratosphere
A trio of NASA satellites observe in synchrony the vertical structures of thunderstorms (lower track) and their influences on ice clouds (color shades), water vapor (contours) and pollutants just above Earth´s lower atmosphere (higher track). Image courtesy of Rong Fu, Cinda Gillilan, Jonathan H. Jiang and Brian Knosp.

NASA and Georgia Tech 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.

Source: Georgia Institute of Technology

Explore further: Suomi NPP satellite spots birth of Tropical Cyclone Kate

add to favorites email to friend print save as pdf

Related Stories

Russia battles to contain Black Sea oil spill

14 hours ago

A Russian Black Sea city declared a state of emergency Thursday after a burst pipeline spewed oil into the landlocked water body, with stormy weather hampering cleanup efforts.

Cyclist's helmet, Volvo car to communicate for safety

Dec 21, 2014

Volvo calls it "a life-saving wearable cycling tech concept." The car maker is referring to a connected car and helmet prototype that enables two-way communication between Volvo drivers and cyclists for proximity ...

Cadillac CT6 will get streaming video mirror

Dec 20, 2014

Cadillac said Thursday it will add high resolution streaming video to the function of a rearview mirror, so that the driver's vision and safety can be enhanced. The technology will debut on the 2016 Cadillac ...

Off-world manufacturing is a go with space printer

Dec 20, 2014

On Friday, the BBC reported on a NASA email exchange with a space station which involved astronauts on the International Space Station using their 3-D printer to make a wrench from instructions sent up in ...

Recommended for you

Suomi NPP satellite spots birth of Tropical Cyclone Kate

Dec 24, 2014

The tropical low pressure area previously known as System 95S organized and strengthened into Tropical Cyclone Kate on Dec. 24 and the Cocos Keeling Islands are expected to feel its effects on Dec. 25 and ...

NASA looks at some severe holiday weather from space

Dec 24, 2014

Severe weather in the form of tornadoes is not something people expect on Christmas week but a storm system on Dec. 23 brought tornadoes to Mississippi, Georgia and Louisiana. As the storm moved, NASA's RapidScat ...

NASA satellite spots Christmas

Dec 24, 2014

If you're looking for Christmas NASA's Aqua satellite spotted it in the Southern Indian Ocean. It's a coral atoll (a ring-shaped reef, island, or chain of islands made up of coral) in the northern Line Islands ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.